Various comments on various posts in this thread: > Good point. If someone chooses to paddle solo in conditions which may > require the use of a skeg or rudder they had better make sure that they > employ a more important piece of equipment; their head, and have the > common sense to make sure that their boat is well maintained and completely > functional. Undoubtedly true, but I hope this isn't being negative about solo paddling, one of life's great pleasures. Ever heard of Murphy's law as applied to skegs? > Paul Caffyn ... is reported to have told Chris that if he didn't use a Nordkapp > >with a deep draft rudder he had no chance of succeeding. ... I remember thinking what a silly comment by Paul, You don't suppose Paul might have been a bit tongue in cheek, perhaps just slightly less than rock solid adamant with that comment do you? > If I had my rudder fitted (fell off years ago and I never put it back) Of course it fell off, they all do at some time don't they? >I think it is useful to check the balance of the boat by lifting it. >Straddle the boat, grasp it under the coaming at the CoB point, and lift >slightly. If both ends come off the ground, OK.This makes sense, but the trick is knowing where the COB is located. Any > thoughts? Matt states the Centre of Buoyancy is near where your navel is. Drop a perpendicular from your belly button and mark the seat with a waterproof marker pen! In practice I am guessing that the location of the CoB along the length of the kayak is around the same point as the Centre of Mass, which may be wrong, but for most kayaks is probably OK for practical purposes. Perhaps you could measure your kayak and put the data into a hull design program, and have the CoB calculated. > However, perception and reality can often be two different things. Until we > get some objective measured results with many different kayaks using both a > rudder and not using a rudder (by paddlers equally competent both ways) we > don't have good data, only opinions. Very true. Even if you have the same paddler try paddling in two different boats in similar conditions, there are so many variables which are hard to control that the trial will never be anything like a mathematical thought experiment. Makes me wonder about those turning tests you conduct to compare different boats. Perhaps one way to make trials better is to conduct many of them. One thousand one mile downwind runs over the same measured course in each boat tested, say. Since that sort of thing is so laborious it won't be done, we only have subjective impressions of kayak performance to go by. I wonder if an analysis of sea kayak race results would be useful. Perhaps one-design sea kayak races, the same hull, variously fitted with rudder, skeg, or none. Nordkapp racing as an Olympic demonstration sport? Go Dougie! The starters will give you an excellent weight-for-age handicap. > With kayaks that don't weather helm you probably ought to store the first 10 > to 20 pounds in front of ones feet (if there is a possibility of extreme > winds blowing off shore anyway) but after that the next 40 pounds should go > into the rear so you won't induce weather helm unnecessarily with a bow > heavy trim. Hey Matt, this is a little different to your recommendation to simply put twice the load in the rear as the front. I think the loading and balancing has to depend upon the particular boat. I still don't like loading differently for different conditions. You may load up for a downwind run, say, and then want to return upwind. Or, the wind may swing. > Lifting the kayak to test the balance only works with light loads and/or strong backs. I suppose there is some back damage risk. If I can do this, I am sure many kayakers can. You only need lift the boat slightly to check the balance. Although I haven't tried this, two paddlers should be able to pass a 2'' sling under the boat and lift to check the balance point. It may be possible to balance the boat on a log if there is one. A check is better than finding the boat misbehaving out on the water. >I'm usually very lightly loaded (day trip) or quite heavily loaded (overnight and longer trips) there doesn't seem to be much middle ground. The middle ground is the FULLY equipped day trip. Folding chairs, coffee brewing, cameras, tripods, novels, tarps, groundsheets, clothing for all occasions, radio, six pack, crackers, dips... :-) Cheers, PT *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Peter Treby [mailto:ptreby_at_ozemail.com.au] wrote:>>> <<< <Snip> > Paul Caffyn ... is reported to have told Chris that if he didn't use a Nordkapp > >with a deep draft rudder he had no chance of succeeding. ... I remember thinking what a silly comment by Paul, >>>You don't suppose Paul might have been a bit tongue in cheek, perhaps just slightly less than rock solid adamant with that comment do you?<<< You'd have to ask Paul. As I recall, Chris reported it as though Paul was very serious. I don't suspect Paul was anything but serious when giving advice to a paddler undertaking what could be a life threatening journey and seeking out his advice and knowledge. I'll bet he believed it and was serious about it (just not correct). I've read Paul's opinions on rudders on more than one occasion and do not share them (except maybe for certain kayaks). They may well work for him in the kayaks he paddles but how many different kayaks has he compared (and what has he had the most practice at). Appeals to authority don't much impress me. > If I had my rudder fitted (fell off years ago and I never put it back) Of course it fell off, they all do at some time don't they? >I think it is useful to check the balance of the boat by lifting it. >Straddle the boat, grasp it under the coaming at the CoB point, and lift >slightly. If both ends come off the ground, OK.This makes sense, but the trick is knowing where the COB is located. Any > thoughts? >>>Matt states the Centre of Buoyancy is near where your navel is. Drop a perpendicular from your belly button and mark the seat with a waterproof marker pen!<<< Not necessarily, lots of kayak designers can't figure it and some who can may purposefully put the seat in another position for a reason. One kayak company, who's new models are rudderless, trims them very stern down and I suspect this is to make them handle better and have less need of a rudder in most conditions. One reason we don't do this (except as a position of the sliding seat) is that there is a drag penalty, at least at faster speeds, with a stern heavy trim. I learned this from doing sprint tests with the sliding seat in various positions. Our original Mariner had an 18" slide range with trim in the middle. With my 180 pounds 9" back from level trim I was 4% slower than at level trim (which was the fastest). Nine inches forward of trim only lost me about 1/2%. Marking the water level at the stern in both extremes of seat position in this 16' or so long waterline showed a 4" vertical difference. That created quite a trim change. Olympic flatwater kayaking experiments have also shown trim to be the fastest, although at one time many believed a bow heavy trim kept the bow from rising as much at hull speed (and that would raise the hull speed limit) the test didn't work out that way. yes the bow didn't come up as high, unfortunately it plowed deeper into the bow wave apparently at greater cost in efficiency than if it could rise higher. >>>In practice I am guessing that the location of the CoB along the length of the kayak is around the same point as the Centre of Mass, which may be wrong, but for most kayaks is probably OK for practical purposes. Perhaps you could measure your kayak and put the data into a hull design program, and have the CoB calculated.<<< If I recall correctly, the center of mass and buoyancy are at the same point (longitudinally and laterally anyway) when the boat is floating. If you move the center of gravity the center of buoyancy changes accordingly because the boat is free to move. In more simple terms the CofB is always directly below the CofG. This can lead to some confusion though because the center of gravity of a kayak you pick up is not the same as it is when it is on the water with a person in it. A Swede-form kayak is likely bow heavy when picked up at the longitudinal center of buoyancy (with a paddler in it) and the opposite for fish-form. it would be impractical to pick up the kayak with the paddler in it (maybe he could climb in when it was balanced over the log though). While it can be done mathematically with great effort (due mostly to all the measurements that must be made). The math itself, Simpson's Rule, I believe is quite easy. However, the easiest way I know of to determine the center of buoyancy of most existing kayaks is with a level. Put the level in front of you in the cockpit (given a reasonably straight or consistently curved keel line in that area--that allows measurements with the level) and then move around in the cockpit until the level is, well, level. Mark the point under your crotch. If using a hull design program it most likely will be able to calculate the center of buoyancy for you (such as Paddlewise's Robert Livingston's--available to download free on our website) . > However, perception and reality can often be two different things. Until we > get some objective measured results with many different kayaks using both a > rudder and not using a rudder (by paddlers equally competent both ways) we > don't have good data, only opinions. >>>Very true. Even if you have the same paddler try paddling in two different boats in similar conditions, there are so many variables which are hard to control that the trial will never be anything like a mathematical thought experiment. Makes me wonder about those turning tests you conduct to compare different boats. Perhaps one way to make trials better is to conduct many of them. One thousand one mile downwind runs over the same measured course in each boat tested, say. Since that sort of thing is so laborious it won't be done, we only have subjective impressions of kayak performance to go by. I wonder if an analysis of sea kayak race results would be useful. Perhaps one-design sea kayak races, the same hull, variously fitted with rudder, skeg, or none. <<< I get excellent repeatability on retesting the same hull. This consistency gives me a certain level of confidence in my timed results. I don't get nearly as good consistency by counting strokes (although I still do as well on the spin tests). The hardest part about your down wind experiment is not that you would have to do very many trials to get reliable results, you wouldn't if they were consistent. It would be the difficulty in keeping the wind and wave conditions even reasonably consistent between even a few runs. Time, wind speed and fetch control wave size. Fetch is the only variable here that you could control. > With kayaks that don't weather helm you probably ought to store the first 10 > to 20 pounds in front of ones feet (if there is a possibility of extreme > winds blowing off shore anyway) but after that the next 40 pounds should go > into the rear so you won't induce weather helm unnecessarily with a bow > heavy trim. >>>Hey Matt, this is a little different to your recommendation to simply put twice the load in the rear as the front. I think the loading and balancing has to depend upon the particular boat. I still don't like loading differently for different conditions. You may load up for a downwind run, say, and then want to return upwind. Or, the wind may swing.<<< Very little difference since my slight modification referred only to a rare class of kayaks, those already balanced in a side wind, and we are only talking about the first few pounds of the load before switching into the 2 to 1 stern to bow GOAL if loading heavier. It should be noted that this goal is rarely achieved with a heavy load so it is very hard to overdo it and not harmful to control if you do. The only penalty for overdoing it is just a little more drag at fast speeds (but much less than a rudder adds). There is no need to load a heavily loaded kayak any different for different conditions. The only time a bow heavy condition would likely be an advantage would be with a light load going into quartering head winds or head seas or in winds so extreme one could barely get the kayak to turn into them (but again with a heavy load this is not likely to be a problem because the ends can't blow around quickly). > Lifting the kayak to test the balance only works with light loads and/or strong backs. >>>I suppose there is some back damage risk. If I can do this, I am sure many kayakers can. You only need lift the boat slightly to check the balance. Although I haven't tried this, two paddlers should be able to pass a 2'' sling under the boat and lift to check the balance point. It may be possible to balance the boat on a log if there is one. A check is better than finding the boat misbehaving out on the water.<<< I've heard the teeter it over a log one before too. With a heavy load this is asking for damage with many kayaks. It is also unnecessary. How many times are you going to have to repack everything to get it right. Even if you get the balance perfect the heavily loaded kayak is likely to handle the more difficult conditions better if it is out of trim some towards the stern (even though in reality this is very hard to achieve given the relative storage volume available in each end if you make it your simple goal the first time you pack you will end up with a better handling kayak the closer you come to achieving that goal. What could be simpler. Load all heavy dense items (and bags) in the stern and the light ones in the bow. It is an easy simple to follow rule and you only have to load the kayak once, no lifting, balancing or logs necessary. One more simple rule. Float the loaded kayak on the water to see that it floats level side to side before getting in. If it doesn't, shift a few liters of water from one side to the other until it floats level. I like to take some of my water in clear 2 liter soft drink bottles because they make this sort of thing easy (and they can be stomped flat for more space when not in use and reconstituted like a balloon if you want to refill them again). Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
> You'd have to ask Paul. Will do. FWIW, I can't imagine anyone seriously suggesting that only one type of kayak can complete challenging trips, although you can read on kayak manufacturer's websites that their kayak is pre-eminently suitable for certain testing trips. > Appeals to authority don't much impress me. Disregard for knowledge and experience is the opposite evil. > ... lots of kayak designers can't figure it ... One kayak > company, who's new models are rudderless, trims them very stern down. Which brand of kayaks are these? Good to see someone is bringing out rudderless models. Don't the centre of buoyancy and the centre of mass line up once the boat is on the water? If the CoM is not aligned vertically with the CoB, doesn't the kayak hull shift in the water until it is? I understand the CoB to be the point through which the forces counteracting sinking appear to act. If the CoM is measured along the kayak when it is out of the water, the difference when the boat is on the water is the mass of the kayaker sitting in it which may alter both centres. If the kayaker's centre of mass is determined to be somewhere in the gut behind the navel, then that point should be aligned vertically over the kayak's centre of mass to have the boat float in trim. Picking the kayak up and balancing it determines the position of the centre of mass of the kayak along its length. Then plonk the boat in the water, and the centre of buoyancy is at that point. Tell me if I'm wrong. > A Swede-form kayak is likely bow heavy when > picked up at the longitudinal center of buoyancy (with a paddler in it) and > the opposite for fish-form. Now I'm lost. If the centre of mass of the paddler and the kayak are aligned vertically, and the boat is at rest on the water, then the centre of buoyancy will align vertically through both those centres, won't it, whatever the plan shape of the hull? Do you mean that because Swede form kayaks likely have more storage room in the stern, and conversely Fish form kayaks more storage room in the bow, that there is a probable difference in the distribution of the load placed in each type? But that depends on how you pack it, which is what we have been discussing. So there is no necessary likelihood that a Swede form boat will be likely to be bow heavy when picked up at the longitudinal centre of buoyancy, because that point, by definition, is lined up with the centre of mass, with or without a paddler in the boat. > However, the easiest way I know of to determine the center of > buoyancy of most existing kayaks is with a level. Since the centre of buoyancy is at the centre of mass of the displaced water, and both are aligned vertically when the kayak is at rest, why isn't the centre of mass of the kayak on land a good approximation to the centre of mass of the water is displaces when floating. Could you explain this use of a level a bit further? > I get excellent repeatability on retesting the same hull. You are way ahead of me. Every time I turn the boat radically, it spins through a different arc. The turning effect depends on a lot of things, including how close to having a cold wet ear I want to be. > Very little difference since my slight modification referred only to a rare > class of kayaks, those already balanced in a side wind... That's something else to think about. What side wind? A kayak balanced in a 10 knot wind will not be a kayak balanced in a 20 knot wind, for the same forward speed of the kayak. I suppose a kayak designer should try for balance in the winds a boat is likely to be paddled in. That will mean that higher winds will weathercock a boat designed to balance in lower winds. And a boat designed to balance at 3.5 knots paddling speed in 15 knots beam wind, will drop off downwind when stationary in the same wind. What approximate beam winds should boats be designed to balance in? >What could be simpler. Load all heavy dense > items (and bags) in the stern and the light ones in the bow. It is an easy > simple to follow rule and you only have to load the kayak once, no lifting, > balancing or logs necessary. Next fully loaded trip I will try this, as far as possible. I will also pick the boat up when it has been loaded and see how it behaves according to the backbreaker test. We may be talking about achieving the same end. I have never had to repack the boat numerous times to achieve fore-and-aft balance on the pick up test. If any adjusting is done, it is just to move say a water container or food bag from back to front or vice versa. Same thing as your lateral adjustment with soft drink bottles. Things trim better with Coke? Cheers, PT *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Peter Treby (>> <<) [mailto:ptreby_at_ozemail.com.au] responded to me (>): > Appeals to authority don't much impress me. >>Disregard for knowledge and experience is the opposite evil.<< Not opposite at all. I've got nothing against authorities, as long as their reasoning is clear. Rather, I object to: "The authority said it so it must be right". Likely he is, but he could also be wrong. I want to hear the argument rather than the name before I decide what I think. > ... lots of kayak designers can't figure it ... One kayak > company, who's new models are rudderless, trims them very stern down. >>Which brand of kayaks are these? Good to see someone is bringing out rudderless models.<< I got this trim information through my drag test work for Sea Kayaker so I'm not sure I'm at liberty to reveal the company. The reason is pure speculation on my part, but I would bet on it. The drag calculations I do for Sea Kayaker don't take the (likely) increased drag of non-level trims into account. I'd like them to but I don't have any hard data that measures the effect reliably enough. Anybody know if that data is available for ships or racing kayaks? >>Don't the centre of buoyancy and the centre of mass line up once the boat is on the water? If the CoM is not aligned vertically with the CoB, doesn't the kayak hull shift in the water until it is? I understand the CoB to be the point through which the forces counteracting sinking appear to act. If the CoM is measured along the kayak when it is out of the water, the difference when the boat is on the water is the mass of the kayaker sitting in it which may alter both centres. If the kayaker's centre of mass is determined to be somewhere in the gut behind the navel, then that point should be aligned vertically over the kayak's centre of mass to have the boat float in trim. Picking the kayak up and balancing it determines the position of the centre of mass of the kayak along its length. Then plonk the boat in the water, and the centre of buoyancy is at that point. Tell me if I'm wrong.<< You're wrong. Let's take it to extremes (things are often clearer that way--a trick my dad taught me). Put a huge amount of weight in the bow (only) and find the kayaks center of mass by lifting it at different places until it balances. Put the kayak in the water and now sit on that balance point (for the sake of example, say the bow hatch). What's going to happen? Well the center of gravity will still end up over the center of buoyancy but the kayak might be nearly vertical in the water when it does so. In order to keep the kayak LEVEL the paddlers weight would have to be further back (far enough back so that the CofB and the CofM lined up when the kayak is LEVEL). > A Swede-form kayak is likely bow heavy when > picked up at the longitudinal center of buoyancy (with a paddler in it) and > the opposite for fish-form. >>Now I'm lost. If the centre of mass of the paddler and the kayak are aligned vertically, and the boat is at rest on the water, then the centre of buoyancy will align vertically through both those centres, won't it, whatever the plan shape of the hull?<< Yes, always but the kayak may or not be level at that time. I may not have been very clear here. Pick the kayak up empty, put a paddler in it on the water. >>Do you mean that because Swede form kayaks likely have more storage room in the stern, and conversely Fish form kayaks more storage room in the bow, that there is a probable difference in the distribution of the load placed in each type? << No, I was talking about an empty kayak and how its mass is distributed. On its own (no paddler in it) it would likely sit in the water with a bow down trim. In order to get a LEVEL trim the paddler will have to sit a little further back in it than in a fish form kayak. > However, the easiest way I know of to determine the center of > buoyancy of most existing kayaks is with a level. >>Since the centre of buoyancy is at the centre of mass of the displaced water, and both are aligned vertically when the kayak is at rest, why isn't the centre of mass of the kayak on land a good approximation to the centre of mass of the water is displaces when floating. Could you explain this use of a level a bit further?<< The level is to find out where the seat has to be in the kayak for the kayak to float LEVEL on the water. You seem to be assuming that when the centers line up the kayak will be LEVEL. But that can't be because the centers always line up when a stable balance is reached but the kayak is only level when that balance is reached and the kayak is still at LEVEL trim. The level helps you easily (no math involved) find when that balance is reached and the kayak is LEVEL. > I get excellent repeatability on retesting the same hull. >>You are way ahead of me. Every time I turn the boat radically, it spins through a different arc. The turning effect depends on a lot of things, including how close to having a cold wet ear I want to be. True, so I need to try to be consistent based on some reasonable and practical standard. Therefore, I have chosen to lean each kayak as far as I reasonably can without taking on a lot of water (as if I don't have a spraydeck that fits the kayak--sometimes none I have access to fit the cockpit). A few splashes are okay but I don't want the water pouring in. In other words I try to use a consistent criteria for the lean. Sure, if I can lean more the turn will be tighter. Some kayaks have such poor knee bracing or are so wide and stable that I can't lean them even that much without undo risk of a capsize. So in those kayaks I lean as far as I can (or as far as I dare to). Since other paddlers will be in roughly the same boat I think this is a logical standard. > Very little difference since my slight modification referred only to a rare > class of kayaks, those already balanced in a side wind... >>That's something else to think about. What side wind? A kayak balanced in a 10 knot wind will not be a kayak balanced in a 20 knot wind, for the same forward speed of the kayak. I suppose a kayak designer should try for balance in the winds a boat is likely to be paddled in. That will mean that higher winds will weathercock a boat designed to balance in lower winds. And a boat designed to balance at 3.5 knots paddling speed in 15 knots beam wind, will drop off downwind when stationary in the same wind. What approximate beam winds should boats be designed to balance in? You are correct that a kayak balanced when moving forward will blow at some angle downwind (where the forces balance) if it is not moving forward. First you are not talking of a huge difference due to different wind speeds (or over normal paddling speed ranges) and secondly you have things backwards at higher speeds. Wind puts more pressure on the end of a long symmetrical object angled into the wind than one angled away. Strong winds (force increases at the square of the wind speed) therefore tend to reduce both weather helm and lee helm. At zero wind speed no kayaks weather helm or lee helm. The weather helm at first gets worse with increasing wind speed but then gets less again in high winds. The worst weather helm is (and this is a subjective guess) in side winds of about 10 knots and the range where it is most of an issue are probably in the 5 to 15 knot range. Since this is also a very common speed range for winds to blow, I try to get the kayak to balance in this wind speed range. The speed of the kayak across the wind doesn't matter as much to this balance as long as one is moving at a reasonable kayaking pace. If it still tend a little one way or the other then adjust the skeg or slide the seat or use the rudder or some lean of the kayak to make it turn to compensate. The closer to neutral you can get the basic kayak hull to be the less energy will be required to make needed corrections. Our goal is to make a kayak neutral when it is moving forward at a good cruising speed. Neutral to the wind and neutral to the waves [in all axis of rotations--yawing (weather helm and broaching), heave/dip, and side to side (dynamic stability in waves)]. A neutral kayak is a kayak that is easy to control because you are not fighting "tendencies" or "forces" all the time. Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
{editing and rearranging done by the moderator since my original only went to Peter and not the list. Peter worked so hard on his response I felt a need to let it get to everyone} > Kirk wrote: > On Thu, 24 Jun 2004 17:15:37 +1000, "Peter Treby" <ptreby_at_ozemail.com.au> said: > > > However, the easiest way I know of to determine the center of > > > buoyancy of most existing kayaks is with a level. > > Since the centre of buoyancy is at the centre of mass of the displaced > > water, and both are aligned vertically when the kayak is at rest, why > > isn't > > the centre of mass of the kayak on land a good approximation to the > > centre > > of mass of the water is displaces when floating. Could you explain this > > use > > of a level a bit further? > > Imagine the "perfect" worst case example. Your boat is made up of two > sheets of plywood. > One sheet perpendicular to the other. The sheet for the front half of the boat lies parallel to the water. The sheet for the back half of the boat is centered on the front sheet but vertical to the water. The CoM is at the intersection of > the two sheets. > Now put your "boat" in the water. The bouyancy of the back section of > the boat water is minimal (assuming most of the plywood is above water. The CoB is > quite a ways into the front sheet of plywood which is parallel to the water. Kirk: A kayak is a three dimensional object. We place it in x,y,z axis coordinates in three dimensions, such that the x axis is the length of the boat, the y axis is the keel to deck height, and the z axis is the beam to beam section. Now assume the kayak to have a shadow construct beside it, comprised of two sheets of plywood at right angles to each other such as you describe. Along which axes are you placing each sheet of plywood? In what relation to each other are the two sheets of plywood? Levelling the floating plywood construct does not give you any information about the centre of buoyancy or the centre of mass. If you make assumptions about uniform distribution of mass, which is OK for a sheet of even thickness plywood, but not for a kayak, or a loaded kayak, or a kayak with a paddler in it, you can float the ply construction, note that it floats level, and confirm that with your level, and project a perpendicular from the centre, vertically, along which the CoM and CoB will lie. Float the kayak. Use the level on the floor of the cockpit. If the level is placed lined up with the z axis, beam to beam, then the CoB will lie on a line perpendicular to the level, up the y axis. If the level is placed along the length of the kayak, the x axis, it may be level, but it does not supply any information about where on the x axis the CoB lies. To locate the CoB, you have to locate the centre of mass of the water displaced by the kayak. You could construct a three dimensional geometric model of the hull shape. You could then assume, when it is a bare hull, that its mass is evenly distributed throughout the volume of the hull. You could then estimate its mass, for a typical construction method. You then assume that when floating it displaces an evenly distributed volume of water. The waterline can then be calculated if you apply considerable mathematical skill to the hull shape. A bit of integral calculus will come in handy. The centre of mass of the displaced water, which is the centre of buoyancy, can no doubt be derived in this way. Hull design programs must use something like this, to arrive at the centre of buoyancy for a hull supporting a given mass, distributed evenly throughout the hull. If you start making assumptions about even distribution of mass in the kayak, you are begging the question we wish to answer, how to load the kayak so that it floats at trim. Mathematics seems the long way. Take the empty kayak. Lift it by the coaming, and note the point, along the x axis, the length, at which it balances. Place the kayak seat so that the paddlers centre of mass will be over the kayak's centre of mass when sitting in the boat. Load the boat so that it balances along the x axis at the same point as when unladen. Float the kayak and get into it. It should then float at trim. Why wouldn't it? Why bother trying to estimate whether you have placed twice the load in the rear as in the front of the boat? If I keep asking stupid questions, we can spank Paddlewise along for years! Cheers, PT *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Matt Broze writes... Not opposite at all. I've got nothing against authorities, as long as.... <<big snip>> one must also realize that the same vessel that 'balances' so nicely in the speeds (both wind and paddling) most people paddle at/in may have a tendency to slide out of that balance as the velocities increase. Even to the point where scootching your seat/footbraces doesn't help. And what about reverse? when going backwards how does this nicely balance hull behave? Was it designed to even go backwards? Most loose tracking, balanced boats will have a tendency to weathercock and most straight tracking hulls will have a tendency to leecock given the 'extreme' example scheme that Matt describes. In a strong offshore breeze here in Oregon, we say "Call me from Japan!" =:-0) steve http://mail2web.com/ . *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Hello Matt: Now where were we? " I never divide or weigh the gear. Twice as much is only a goal to shoot for. I shoot for it by packing every heavy dense bag (and water) that I can into the stern and then put what won't fit there into the bow..." One negative with all the heavy gear in the stern is that some heavy gear will be out at the very stern, offending the aim usually advocated for maximum manoevrability, of having heavy gear located in the centre of the boat, and leaving the ends light. I suspect this 2:1 trim may not achieve a good result for fish form kayaks with thin cross sections in the stern, like a Nordkapp. I am now interested to try this, or more interesting, induce some of my paddling friends to try it and see what the trim of their boats might look like, and how they behave. > Only in kayaks that float level when empty...You seem to be assuming that when the centers line up the kayak will be LEVEL.>OF COURSE I have been assuming that an unladen kayak floated on the water will be trim and level. It seems to be the case with all sea kayaks with which I am familiar.<< [the contrary=] Most Mariner kayaks for several. I hazard a guess, without data, that Mariner kayaks are at the extreme of the swede form long bow design, so that my assumption re empty-boat-level-trim is true of many sea kayaks, and true enough of most. Anyone on the list have a boat which is noticeably out of level trim when placed on the water empty? > In particular, can you name a swede form kayak that requires this? If you > can, the distance will be so small that it will not have any practical > effect on the trim method I have described above.Since most kayaks don't >have a seat you can easily move it is a moot point about getting the paddlers >weight over the center of gravity of the kayak anyway >(with a level trim). With a fixed kayak seat you need to play with the hand >that the kayak designer dealt you. Now this is interesting . How many new boats are sold with any advice as to trim? Your owner's manual contains advice, maybe you are an exception. Many boats are purchased second hand. How is the kayak owner to know what the intended trim is,if he or she cannot assume that the unladen kayak will float at level trim? Perhaps not many boats are sold with a level. Perhaps it is not necessary, as most boats float level unladen, or at least level enough, and close enough to suitable trim so that body movement is enough to make the boat work OK. Are Mariner kayaks in a small minority here? >why not just bring a small level with you and once you've gotten into the floating kayak check > that the kayak is now level (or slightly stern heavy if loaded with gear) Well, a high percentage of my launches are not onto calm water, and I do not want to take redundant one-off use gear like a level. How would the folding chair fit in? I want a practical trimming method, if trim is important, that can be used without extra gear. Do you take a level with you every time you are using a loaded boat? More level problems: the point where you want to know that the kayak is level is obstructed by the seat and fittings, making you level it at a point forward of the seat, at least theoretically not the correct point to measure level trim. In practice that is close enough if the keel there runs level. In some boats, due to the hull form there may be no suitable point to place the level. Re the plane-in-a-wind-tunnel-at-45-degrees: I see that you meant the combination of forces on a free moving kayak, and not what you said. >If the wind is blowing such that it hits end "A" first > that end will have more pressure on it than end "B". After a brief moment, the wind pressure is equal along the length. >What kayak do you paddle? A swede form boat with chines at the stern and a bloated V bow. Sound familiar? >When sitting still in a side wind does your kayak blow straight sideways or slightly bow or stern down wind? Fairly quickly bow downwind, so that it is balanced in moderate winds at usual paddling speeds. I like that. I am still now intrigued as to a practical method of finding the design trim of a boat, given that a level assumes the keel line it is placed along is suitable for level trim. What about those boats you decline to name? Will the intended design trim be uphill towards the bow? No kayak manufacturer paints a waterline on the boat. Is that the only really definitive way to determine ideal trim? Rambling thoughts, it is late, Cheers, PT *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On 28 Jun 2004 at 22:03, Peter Treby wrote: > One negative with all the heavy gear in the stern is that some heavy > gear will be out at the very stern, offending the aim usually > advocated for maximum manoevrability, of having heavy gear located in > the centre of the boat, and leaving the ends light. In fact, this point makes the 2:1 ratio questionable as a guide. I could probably come up with a kayak and gear arrangement that achieves the identical balance with 1:1 weight simply by judicious choice of which gear goes where. However, it would not necessarily snap around due to rotational inertia about the vertical axis. 2:1 may only apply if we are rigorous about placing the load in a certain way - massive items near the cockpit and light objects near the ends. But then, sometimes ballasting with weight in the ends can have a useful damping effect on pitching. I've been thinking of this on the weekend - if we rely on weight distribution to minimize need for a skeg/rudder, we risk goofing and not being able to adjust on the water. If we rig a sliding seat to correct on the fly, we have simply replaced one form of mechanism that can fail with another. Regardless of goofs, I know that my kayak needs slightly different skeg settings for wind on the starboard or port bow versus wind on the quarters. Given the simplicity of the most basic skeg designs (rope and cleat rather than silly little sliders and Bowden cables), I don't see much point in avoiding them. The skeg box's blockage of the stern storage area is a minor annoyance IMHO. Mike BTW, Nimbus (Rainforest Designs) kayaks all have sliding seats. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Michael Daly wrote: > > But then, sometimes ballasting with weight in the ends can > have a useful damping effect on pitching. This may be true in some rare cases but my experience in a wide variety of boats, sail, power, paddle, etc. shows that pitching usually increases with weight in the ends of the boat. It is far better to control pitching with buoyancy and hull shape. Having the ends shaped differently, that is the buoyancy and change in buoyancy with immersion is different between the bow and stern does more to damp pitching. For good examples see the designs (multihull sailboats) of Kurt Hughes at; http://www.multihulldesigns.com/ While the shapes he uses would likely not be all that great for kayaks the idea is sound. Ever notice that there are more fish form, and swede form kayaks than symmetrical ones? Think there might be a reason? And yes, sometimes the added inertia DOES help the boat punch through small waves instead of pitching so weight in the ends will help *sometimes*. michael (still more sailor than kayaker) *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Peter Treby [mailto:ptreby_at_ozemail.com.au] wrote:>> << >>(quoting me in quotes: " I never divide or weigh the gear. Twice as much is only a goal to shoot for. I shoot for it by packing every heavy dense bag (and water) that I can into the stern and then put what won't fit there into the bow..." One negative with all the heavy gear in the stern is that some heavy gear will be out at the very stern, offending the aim usually advocated for maximum manoevrability, of having heavy gear located in the centre of the boat, and leaving the ends light.<< This factor is usually way overblown. The major problems caused by it is due to too much weight in the bow (spearing the waves and increasing the heave/dip of the hull). If the goal is a better handling gear laden kayak, one would be wise to load the kayak stern heavy enough to minimize the weather helm and broaching. I usually put the water right behind my seat so as to keep it as close to the center as possible (any water in front of my feet would be a whole lot further from the CofB). However, once using a rental kayak on a week trip in Baja I found that it handled a whole lot better (in side winds and following seas) when I put some of my water all the way in the stern. >>I suspect this 2:1 trim may not achieve a good result for fish form kayaks with thin cross sections in the stern, like a Nordkapp. I am now interested to try this, or more interesting, induce some of my paddling friends to try it and see what the trim of their boats might look like, and how they behave.<< Given the reduced volume aft in a Nordkapp I'd still try to put as much of the weight as I could in the stern to help keep the kayak at trim with a gear load. The reality is that getting twice as much weight in the back would not likely be achieved, but it wouldn't hurt to have that your goal as you then might actually get enough back there not to have that kayak bow heavy and weather helming. Of course if we are talking an HM version the tracking is so stiff already one should try not to make it trim stern down because that will make it even harder to turn. > Only in kayaks that float level when empty...You seem to be assuming that when the centers line up the kayak will be LEVEL.> >>OF COURSE I have been assuming that an unladen kayak floated on the water will be trim and level. It seems to be the case with all sea kayaks with which I am familiar.<< [the contrary=] >Most Mariner kayaks for several.< >>I hazard a guess, without data, that Mariner kayaks are at the extreme of the swede form long bow design, so that my assumption re empty-boat-level-trim is true of many sea kayaks, and true enough of most. Anyone on the list have a boat which is noticeably out of level trim when placed on the water empty?<< You didn't say which kayak you own but it may be just as extreme as any Mariner (if my guess is correct). Possibly you yourself have an out of trim kayak when empty, especially if my guess is correct on which kayak you own. Noticeable is in the eye of the beholder though. An out of trim weight distribution would be a lot more noticeable when picking it up (and discovering the center of balance is forward of the front of the seat) than it would be when floating on the water. When a kayak is sitting on the water one is unlikely to notice a few (very significant) degrees of angle difference in trim just by looking at it. >Since most kayaks don't >have a seat you can easily move it is a moot point about getting the paddlers >weight over the center of gravity of the kayak anyway >(with a level trim). With a fixed kayak seat you need to play with the hand >that the kayak designer dealt you. >>Now this is interesting . How many new boats are sold with any advice as to trim? Your owner's manual contains advice, maybe you are an exception. Many boats are purchased second hand. How is the kayak owner to know what the intended trim is,if he or she cannot assume that the unladen kayak will float at level trim? Perhaps not many boats are sold with a level. Perhaps it is not necessary, as most boats float level unladen, or at least level enough, and close enough to suitable trim so that body movement is enough to make the boat work OK. Are Mariner kayaks in a small minority here?<< Hopefully the designer will have placed the seat such that the boat is either in trim or where the designer has determined the best trim to operate the empty kayak would be (if he thought about it at all). I think you are making this all to complicated. The question is how to load a kayak for best all around performance considering the conditions one might be exposed to. Even if the designer totally screwed up one can still load the kayak in such a way as to optimize its performance (even if that performance is still bad relative to some other kayaks). >why not just bring a small level with you and once you've gotten into the floating kayak check > that the kayak is now level (or slightly stern heavy if loaded with gear) >>Well, a high percentage of my launches are not onto calm water, and I do not want to take redundant one-off use gear like a level. How would the folding chair fit in? I want a practical trimming method, if trim is important, that can be used without extra gear. Do you take a level with you every time you are using a loaded boat?<< No only when I'm checking the trim of a kayak to either determine the seat placement or to check if the boat I'm wondering about is as out of trim as it looks like it might be. My method is much simpler. I follow a simple rule for a heavy gear load: "Put all the densest stuff in the back." It doesn't much matter where level trim is when you are looking for the best handling performance, what matters is to get the best handling without messing some other important factor up too much. >>More level problems: the point where you want to know that the kayak is level is obstructed by the seat and fittings, making you level it at a point forward of the seat, at least theoretically not the correct point to measure level trim. In practice that is close enough if the keel there runs level. In some boats, due to the hull form there may be no suitable point to place the level.<< Sure there are exceptions and if you go back and read my original statements I'm confident that I left room for them in what I wrote. With ninety plus percent of sea kayaks you will be able to use a level just in front of the seat to reasonably accurately check the trim (if you want to get that picky about it). I'm not that picky except when I'm designing the kayak. It is hard to get too much weight in the stern of any fully loaded kayak and the consequences of overdoing it are minimal compared with not getting enough in the back. >>Re the plane-in-a-wind-tunnel-at-45-degrees: I see that you meant the combination of forces on a free moving kayak, and not what you said.<< >If the wind is blowing such that it hits end "A" first > that end will have more pressure on it than end "B". >>After a brief moment, the wind pressure is equal along the length.<< No, I meant exactly what I said. The wind pressure will be greater on the end of a long symmetrical object more pointed into the wind. This will continue to be so until that objects turns exactly crosswise to the wind. Please look this up and show me a text that contradicts me before continuing with this part of the thread. >What kayak do you paddle? A swede form boat with chines at the stern and a bloated V bow. Sound familiar? It sounds like maybe I'm the hull designer. Is it the Nagdee Expedition? >When sitting still in a side wind does your kayak blow straight sideways or slightly bow or stern down wind? >>Fairly quickly bow downwind, so that it is balanced in moderate winds at usual paddling speeds. I like that.<< So do I. It sound even more like I designed it. I'll ask again. What model is it? >>I am still now intrigued as to a practical method of finding the design trim of a boat, given that a level assumes the keel line it is placed along is suitable for level trim. What about those boats you decline to name? Will the intended design trim be uphill towards the bow? No kayak manufacturer paints a waterline on the boat. Is that the only really definitive way to determine ideal trim? Rambling thoughts, it is late,<< One of the unnamed kayaks had a stern down trim of about 3" (nearly 2 degrees). I'd determine the ideal trim with some experimentation with different loads in different conditions. Then I'd try to repeat the loading that made the kayak handle the best in the worst of conditions. Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Matt: > having heavy gear located in the centre of the boat, and leaving the ends light...This factor is usually way overblown... > I usually put the water right behind my seat so > as to keep it as close to the center as possible. Sounds like you take some account of the light end idea. > You didn't say which kayak you own but it may be just as extreme as any > Mariner (if my guess is correct). No guess necessary, as posted several times, a Nadgee Expedition. What is the hull design history of this boat? Perhaps both Mariners and the Nadgee are unusual sea kayaks if they share the quality of having the centre of gravity of the empty boat significantly away from the point at which level trim would be measured. I think quite a lot of boats would have it closer, but after this discussion, I will be taking note when picking up kayaks. > Possibly you yourself have an out of trim kayak when empty. Since we haven't really pinned down what trim means, this is hard to establish. You mean trim when a boat floats level as measured by a level parallel to the keel at or just forward of the seat? If so, "trim" is not defined by the distribution of mass of the kayak when carried. It just means level at a certain point. Isn't a vessel trim when it floats at the intended waterline? >I think you are making this all too complicated. I keep it simple really. I just balance the loaded kayak at around the middle of the cockpit. I pick it up to test that. > The question is how to load a kayak for best all around >performance considering the conditions one might be exposed to. Do you try and load differently for different conditions? I am not attracted to that. Conditions change during a day's paddling. > I'd determine the ideal trim with some experimentation with > different loads in different conditions. Then I'd try to repeat the loading > that made the kayak handle the best in the worst of conditions. Well, I'd just get the thing level, without using a level. Cheers, PT *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
From: Peter Treby [mailto:ptreby_at_ozemail.com.au] wrote:>> << Matt: > having heavy gear located in the centre of the boat, and leaving the ends light...This factor is usually way overblown... > I usually put the water right behind my seat so > as to keep it as close to the center as possible. >>Sounds like you take some account of the light end idea.<< Sure, but I'm not married to it and think it is overemphasized so it is a "rule" it readily break if there was much benefit to do so. > You didn't say which kayak you own but it may be just as extreme as any > Mariner (if my guess is correct). >>No guess necessary, as posted several times, a Nadgee Expedition. What is the hull design history of this boat? Perhaps both Mariners and the Nadgee are unusual sea kayaks if they share the quality of having the centre of gravity of the empty boat significantly away from the point at which level trim would be measured. I think quite a lot of boats would have it closer, but after this discussion, I will be taking note when picking up kayaks.<< Well from your description it was an educated guess on my part that it was the Nadgee. I didn't remember (if I ever knew) what you paddled. I even looked up Paddlewise's Who's Who to see if my guess was right but I couldn't find a listing for you there. Truth be known, the Nadgee Expedition is extremely similar to a Mariner Max because I pretty much designed its hull. > Possibly you yourself have an out of trim kayak when empty. >>Since we haven't really pinned down what trim means, this is hard to establish. You mean trim when a boat floats level as measured by a level parallel to the keel at or just forward of the seat? If so, "trim" is not defined by the distribution of mass of the kayak when carried. It just means level at a certain point. Isn't a vessel trim when it floats at the intended waterline?<< Personally, I'd agree with your last sentence, but most ship hulls are designed so that their keel is level when at rest because this is the most efficient trim for them. Efficiency spells big dollar savings to a ship owner given the high price of fuel. >I think you are making this all too complicated. I keep it simple really. I just balance the loaded kayak at around the middle of the cockpit. I pick it up to test that. > The question is how to load a kayak for best all around >performance considering the conditions one might be exposed to. Do you try and load differently for different conditions? I am not attracted to that. Conditions change during a day's paddling. Not usually but I might be tempted if I knew what conditions I would be facing and the price of being wrong wasn't very high. This would be more likely with a small or partial gear load where I would have a wider latitude of choices. > I'd determine the ideal trim with some experimentation with > different loads in different conditions. Then I'd try to repeat the loading > that made the kayak handle the best in the worst of conditions. >>Well, I'd just get the thing level, without using a level.<< To each his own. Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On 30 Jun 2004 at 0:30, Matt Broze wrote: > Personally, I'd agree with your last sentence, but most ship hulls are > designed so that their keel is level when at rest because this is the > most efficient trim for them. Efficiency spells big dollar savings to > a ship owner given the high price of fuel. Actually, big ships are not level when sitting still. The thrust from the props changes the trim, so they are designed and loaded to be out of trim when at rest and the thrust brings them to trim when under way. Mike *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Hi all. I'm heading for Hotsprings Cove (West Coast Vancouver Island) next week and was wondering where others have set up camp when there? Last time I was there I camped on a beach opposite the government dock that turned out to be indian reserve land - oops! - I didn't notice until we were packing up, fortunately nothing came of it. I was hoping to hit the springs after the flotilla of tourists have left for the day and since this most likely will mean paddling back in the dark I was hoping that we could camp right in the cove and not on Flores Island. Is camping permissible near the government dock? Any ideas? Doug, Kirby? Thanks Steve Davis Victoria, BC *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
> Hi all. I'm heading for Hotsprings Cove (West Coast Vancouver Island) next week and was wondering where others have set up camp when there? Last time I was there I camped on a beach opposite the government dock that turned out to be indian reserve land - oops! - I didn't notice until we were packing up, fortunately nothing came of it. I was hoping to hit the springs after the flotilla of tourists have left for the day and since this most likely will mean paddling back in the dark I was hoping that we could camp right in the cove and not on Flores Island. > > Is camping permissible near the government dock? Any ideas? Doug, Kirby? This is what I've been planning for last several years :-).... Yes, there is a reserve on the peninsula where this hot srping is located. I've been told they charge for camping there. But here is a good news: if I'm not mistaken, there is a provincial park right across the bay, 1 or 2 miles away, and camping is allowed there. So you could cross the bay, leave your boat at the dock and go soak. I think you'll find park description here (go to Park Finder): http://wlapwww.gov.bc.ca/bcparks/ . How long did it take to get there (or did you make stops on the way from Tofino), and what were conditions llike at the open crossing section? *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
[Moderator's Note: Content unaltered. Excessive quoting (including headers/footers/sig lines/extraneous text from previous posts, etc.) have been removed. Please edit quoted material in addition to removing header/trailers when replying to posts.] Yes, there is camping within Hotsprings Cove. There is a small section of private land near the head of the cove that people can pay to camp on. The trail to the left at the government dock leads to the site. Kirby From: alex Subject: Re: [Paddlewise] Hotsprings Cove > Hi all. I'm heading for Hotsprings Cove (West Coast Vancouver Island) next week and was wondering where others have set up camp when there? Last time I was there I camped on a beach opposite the government dock that turned out to be indian reserve land - oops! - I didn't notice until we were packing up, fortunately nothing came of it. I was hoping to hit the springs after the flotilla of tourists have left for the day and since this most likely will mean paddling back in the dark I was hoping that we could camp right in the cove and not on Flores Island. > > Is camping permissible near the government dock? Any ideas? Doug, Kirby? *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Thanks Kirby and Alex. I'll look into it. The last time we spent two days getting to Hotsprings Cove. The first day we got a late start and ran into strong head winds so we stopped that night at a little buggy beach on Vargas Island. The following day we paddled via the outside of Flores to the cove. It's a great paddle, we counted seven grey whales in Cow Bay. However the outside is pretty exposed without anywhere to run if things blow up so be sure of your weather. In bad weather the inside route would be more prudent. The beach we stayed on wasn't identified as reserve land on the main chart but it was noted on the inset detail of the cove. Like I said before we didn't have any problems, most likely because we arrived late and left early the next day under the cover of fog. I'll be checking out the alternative spots this time round. The best time to go to the springs themselves is early in the morning or at dusk when the zodiacs and floatplanes aren't bringing in the tourists from Tofino. We also spent two days coming back via the inside of Flores and the outside of Vargas, stopping for the night at Whitesands. The end result was a figure eight route around the two islands taking three nights and four days. I think it's quite possible to make Hotsprings in one day but it would be a grind. alex <al.m_at_3web.net> wrote: > Hi all. I'm heading for Hotsprings Cove (West Coast Vancouver Island) next week and was wondering where others have set up camp when there? Last time I was there I camped on a beach opposite the government dock that turned out to be indian reserve land - oops! - I didn't notice until we were packing up, fortunately nothing came of it. I was hoping to hit the springs after the flotilla of tourists have left for the day and since this most likely will mean paddling back in the dark I was hoping that we could camp right in the cove and not on Flores Island. > > Is camping permissible near the government dock? Any ideas? Doug, Kirby? This is what I've been planning for last several years :-).... Yes, there is a reserve on the peninsula where this hot srping is located. I've been told they charge for camping there. But here is a good news: if I'm not mistaken, there is a provincial park right across the bay, 1 or 2 miles away, and camping is allowed there. So you could cross the bay, leave your boat at the dock and go soak. I think you'll find park description here (go to Park Finder): http://wlapwww.gov.bc.ca/bcparks/ . How long did it take to get there (or did you make stops on the way from Tofino), and what were conditions llike at the open crossing section? *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
It's been several years since I've been to Hotsprings Cove, but we stayed at the campground at Maquinna Provincial Marine Park. This worked for us as we were heading back to Toffino after being out for almost two weeks, and it was a nice way to slowly get reitroduced back into civilization. That, and we had an injured paddler for whom we needed to get transportation back to Toffino. There is a hike from the campground to the hotsprings which goes for some distance through the forest, a large portion of which is along a cedar shingled walkway. Over the years Mariners who have visited this place have carved their names and the date that they visited into the shingles along the path. Many of these carvings are quite ornate works of art in their own rite. I enjoyed viewing the carvings along the walkway almost as much as I enjoyed the hotsprings themselves. But like I said, it's been quite a few years since I've been out there and I'm sure others on the list will have more up to date info. Scott So.Cal. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Hi all. I'm heading for Hotsprings Cove (West Coast Vancouver Island) next week and was wondering where others have set up camp when there? Last time I was there I camped on a beach opposite the government dock that turned out to be indian reserve land - oops! - I didn't notice until we were packing up, fortunately nothing came of it. I was hoping to hit the springs after the flotilla of tourists have left for the day and since this most likely will mean paddling back in the dark I was hoping that we could camp right in the cove and not on Flores Island. Is camping permissible near the government dock? Any ideas? Doug, Kirby? Thanks Steve Davis Victoria, BC *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Steve posted: >Thanks Kirby and Alex. I'll look into it. The last time we spent two days getting to Hotsprings Cove. The first day we got a late start and ran into strong head winds so we stopped that night at a little buggy beach on Vargas Island. < One would normally expect a standard n/westerly headwind as the day unfolded. >The following day we paddled via the outside of Flores to the cove. It's a great paddle, we counted seven grey whales in Cow Bay. However the outside is pretty exposed without anywhere to run if things blow up so be sure of your weather. In bad weather the inside route would be more prudent.< Bad weather isn't too bad for a good paddler - it's when it's bad AND packed in solid suddenly with fog. I hate that. Rafael Point is where a lot of paddlers get into trouble, even on seemingly good days as they come around the corner. Also, if rain is expected, don't camp on a steep seaward facing slop, unless you really like it wet. >The beach we stayed on wasn't identified as reserve land on the main chart but it was noted on the inset detail of the cove. Like I said before we didn't have any problems, most likely because we arrived late and left early the next day under the cover of fog. I'll be checking out the alternative spots this time round.< I only commando camp on IR land in an emergency or with prior permission. >The best time to go to the springs themselves is early in the morning or at dusk when the zodiacs and floatplanes aren't bringing in the tourists from Tofino.< Agreed, but daytime off-season is still the best. I find a bit later in September can be awesome, when everyone is back at school and the crowds have died down and the wind has died down. There's nice camping just north up the coast between Hot Springs and Hesquiat (called the Seal Coastline by some locals). Easy to get in and out of in September. >We also spent two days coming back via the inside of Flores and the outside of Vargas, stopping for the night at Whitesands. The end result was a figure eight route around the two islands taking three nights and four days. I think it's quite possible to make Hotsprings in one day but it would be a grind.< Not worth the grind. However, a one day run back to Tofino with reasonably agreeable currents and the wind on your tail is a nice days paddle. Back in the early eighties, Hot Springs Cove was the undressed capitol of the world. Now everyone wears clothes. Such lament. I normally don't hike in the the springs, preferring to wet-exit, then re-enter and roll, whence to depart. Seal-landing your body takes a bit of skill in the swirling bay at the springs (tie-off to kelp beds). If you like your coastal kayaking (which I do for certain venues), here's a site with a list of possibilities: http://www.island.net/~bcamp/#GGGG Good paddling. Don't bump into too many whales, Zodiacs, float planes, other kayakers, water taxis, aluminium whale-watching vessels, etc. If that blond German girl is skinny-dipping at the springs again, pls send digital images. :-) Doug Lloyd Victoria BC *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Recently someone posted what I thought was a great idea...using inflatable fenders to roll a loaded kayak out of the water. I have a bad back, and have been unloading the kayak while it floats in the water, which is fine but not perfect, especially when a bit chilled. I went to West Marine today and the only kind they had required a needle and pump for inflation. Just curious, is this the system used, or do fenders exist that can be blown up by mouth and still be firm enough to protect the keel? Thanks (and if by chance that message was from a different board, my apologies), Lyn *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On 4 Jul 2004 at 21:01, Lyn Goldsmith wrote: > Recently someone posted what I thought was a great idea...using > inflatable fenders to roll a loaded kayak out of the water. Around here (Georgian bay and environs), folks tend to use pool noodles. They come in different diameters and the largest are the best. Notable for being cheap and light, you can get two or three kayak haulers out of one noodle. Other folks use "Squaller Haulers" (named by White Squall, a local kayaking retailer, trip and instruction outfit). These are 2x4 wood bits about half a meter long that have been cut on one side with a broad V. They lie so that the 4 inch side is down are 2 inch thick. They can be used to pull up a kayak and will keep a kayak off the rock when on land. The V shape keeps the kayak from sliding sideways if not on a perfectly flat surface. I made two for Amie from a 2x4 we found on a beach - took about 2 minutes on a bandsaw. I know folks that use minicell foam blocks - the same ones that are used to transport kayaks on car roofs. They tend to be stickier than the noodles though, so sliding is not as easy. All these options are cheaper and lighter than boat fenders. The only advantage to a boat fender is if you find one, the cost is $0. > I went to West Marine today and the > only kind they had required a needle and pump for inflation. Just > curious, is this the system used, or do fenders exist that can be > blown up by mouth and still be firm enough to protect the keel? I've never seen one that wasn't inflated with a football needle. Mike *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
> Recently someone posted what I thought was a great idea...using > inflatable fenders to roll a loaded kayak > out of the water. I have a bad back, and have been unloading the kayak > while it floats in the water, which > is fine but not perfect, especially when a bit chilled. I went to West > Marine today and the only kind they had > required a needle and pump for inflation. Just curious, is this the > system used, or do fenders exist that can > be blown up by mouth and still be firm enough to protect the keel? These can be blown by mouth: http://www.praktek.com/products/BeachRollers/roller200.htm I've bought them recently for future expeditions with a floding kayak. Large balloon wheels like Roleeze can do the job as well, but are impracticable to store on board. Didn't try these "rollers" yet. I'm sure they are firm enough to protect the keel, since capacity is 200 kg (500 lbs). Material seems to be thinner than in fenders, but thery are also cheaper. You'll need at least 2 such rollers or fenders (3 is better). *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On 6 Jul 2004 at 11:43, alex wrote: > You'll need at least 2 such rollers or fenders (3 is better). You only need one if the terrain you paddle in is relatively flat. Most folks I know carry two at most, and that's because they are fanatical about not scratching their hull. Once on land, the second is used to keep the hull off the ground. Here's a photo of one that got away after the kayak was hauled up. Sorry for the quality, but the photo's blown up a lot: <http://www.greatlakeskayaker.ca/lindaUsesHerNoodle.htm> Mike *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
> You only need one if the terrain you paddle in is relatively flat. > Most folks I know carry two at most, and that's because they are > fanatical about not scratching their hull. Once on land, the second > is used to keep the hull off the ground. > > Here's a photo of one that got away after the kayak was hauled up. > Sorry for the quality, but the photo's blown up a lot: > > <http://www.greatlakeskayaker.ca/lindaUsesHerNoodle.htm> For a folding kayak there is another reason to use 2 rollers rather than 1 - to distribute stress on frame more evenly. Their frames are not made for stress concentrated in one point, especially when loaded with camping stuff and food. With a 24" hardshell kayak 10"-12" wheels provide quite adequate rolling on most terrains, but not over large boulders, of course. It also provides easy transporting from parking lot to launch site. Unfortunately, all compact commercial carts (from which Primex/Roleeze is the best), are expensive, too bulky and poorly handle anything except for boat - no bags etc; I had to make my own. Still, Primex with 10" wheels taken off should fit inside a 23"-24" hull on a weekend overnight trip. But noodles is interesting; I think, it can be stored under bungey cords on deck, being light and thin. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Note: this post is out of order (it should have been dated Friday June 25th 1:45AM and have been at the start of digest 2203) because Peter and I accidentally went back channel when we really didn't mean to because I forgot to add "Paddlewise" to the "To" line when I first sent the previous post before correcting the word "sack" to "sake" and sending it on to Paddlewise. Then Peter wrote back just to me thinking I wanted to go back channel. Because Paddlewise was not listed on the to line I assumed he wanted to go back channel and wrote the following post to him. Upon realizing what happened we agreed to put this back on Paddlewise but his answer to the following post has preceded this post. To the few who may have been trying to follow this thread I'm sorry for the confusion. Wrote Peter: I don't see a "Paddlewise" on the "To" line. Are we now back channel? I'll treat it that way unless I see your post in the Paddlewise digest. See my comments inserted into your text below. Matt Broze www.marinerkayaks.com -----Original Message----- From: Peter Treby [mailto:ptreby_at_ozemail.com.au] Sent: Friday, June 25, 2004 1:45 AM To: mkayaks_at_oz.net Subject: Re: Skeg Jammers etc Hello Matt: > Picking the kayak up and balancing it determines the position of the centre > of mass of the kayak along its length. Then plonk the boat in the water, and > the centre of buoyancy is at that point. Tell me if I'm wrong.<< > You're wrong. >>I don't think so. And certainly not by the example you give which follows:-<< I believe you were wrong on the previous paragraph to the one you listed here (which was included in the block of text I was originally commenting on). The following thought experiment I wrote refers to that previous paragraph as well (and is also in agreement with the paragraph you listed above just like you said). > Put a huge amount of weight in the bow > (only) and find the kayaks center of mass by lifting it at different places > until it balances. Put the kayak in the water and now sit on that balance > point (for the sake of example, say the bow hatch). ... In order to > keep the kayak LEVEL the paddlers weight would have to be further back (far > enough back so that the CofB and the CofM lined up when the kayak is LEVEL). >>In this example you agree with my proposition above. Rather than continue to talk at odds, and pick up every wrong point, let me state this suggested method for trimming a sea kayak, without dividing your gear into two piles one twice as heavy as the other.<< I never divide or weigh the gear. Twice as much is only a goal to shoot for. I shoot for it by packing every heavy dense bag (and water) that I can into the stern and then put what won't fit there into the bow. What could be more convenient? It doesn't even matter if I overshoot my goal since all I will loose is a little top speed. A heavily loaded kayak is not as much affected by the wind so turning into a strong one is much easier than when empty and since most kayaks weather helm at trim this stern heavy trim will lessen that tendency some. >>We want to determine a convenient method of deciding if a kayak will float at trim, with its paddler and load on board. We pick up the unloaded boat, and find the balance point, which will be somewhere along the cockpit. We note that point. We locate the seat such that the paddler's CofM will be at the balance point just found. We load the boat with gear. We again pick up the boat at the previously found point, then adjust the gear until the boat again balances fore and aft. We put the boat on the water and get in. The boat then floats trim and level. You may care to disagree with this, or introduce other considerations, but it works.<< Only in kayaks that float level when empty. In those that don't you will be putting the seat in the wrong place and compounding the problem (by putting more weight behind it--not necessarily changing the out of trim angle--although it might do that too depending on the shape of the kayak and how the underwater shape changes as it sinks deeper with more weight in it). >...talking about an empty kayak and how its mass is distributed. On > its own (no paddler in it) it [swede form kayak] would likely sit in the water with a bow down > trim. In order to get a LEVEL trim the paddler will have to sit a little > further back in it than in a fish form kayak. and >You seem to be assuming that when the centers > line up the kayak will be LEVEL. >>OF COURSE I have been assuming that an unladen kayak floated on the water will be trim and level. It seems to be the case with all sea kayaks with which I am familiar.<< That is a pretty big assumption. Have you been checking this with a level? No kayak manufacturer paints a plimsoll line along the boat like a freighter. Do you know of any kayaks which are not level when they are on the water unladen? Yes, several for sure and I suspect that few if any are really absolutely level although it might not be apparent without checking with the level. Your own kayak may be so close that your method works fine for you. It wouldn't work with most of my kayaks. >>Is this anything more than a theoretical point? Can you name a kayak which requires the paddler to place his or her CofM at a point other than at the CofM of the unladen kayak to make it trim?<< Most Mariner kayaks for several. Any Swede-form kayak with more overhang at the bow than at the stern will likely be bow heavy too. A longer bow overhang will tend to help balance out a fish-form kayak though. Remember that any bow overhang is way further out on the teeter-totter with a Swede-form kayak. Many Mariners are so radically Swede-form that the physical balance point (CofM) is often very near the very front of the cockpit. Take it to extremes. Float a barely floating flat triangular piece of wood with two very long sides and one very short side in the water after finding its balance point. (if you divide each angle in half where those three lines intersect should be the balance point). Notice how much further the balance point is from the sharp end. Now build the above waterline part on such a "kayak" on this triangle. I think you would find it very difficult to not sink the bow more than the stern. When you are picking up a kayak you aren't just picking up the part where the water will be supporting it. Any weight you add in each end will effect trim as well (unless you balance how far that weight is from the fulcrum with the amount of weight added). >>In particular, can you name a swede form kayak that requires this? If you can, the distance will be so small that it will not have any practical effect on the trim method I have described above.<< Yes it will, we obviously couldn't place the seat so our belly button presses into the pointed front of the cockpit. Besides being physically impossible to do we would also just be aggravating the out of trim situation and make it much harder to get enough gear weight in the stern to correct all of our own weight we also added forward of the level trim Center of Buoyancy point. Much better to put the heavy paddler further back to balance out both the bow down trim and the uneven weight/distance multiple you've put in each end when loading. Since most kayaks don't have a seat you can easily move it is a moot point about getting the paddlers weight over the center of gravity of the kayak anyway (with a level trim). With a fixed kayak seat you need to play with the hand that the kayak designer dealt you. Your balancing method will work only if the physical balance point of the kayaks mass and the kayaks seat line up in the same place and the kayak floats level both empty and when the paddler is sitting in it at that time. That is a lot to ask. Consider, the paddler sitting in it will sink the kayak deeper in the water. What happens to trim if the bow sections are vertical above the old waterline and the stern sections are extremely flared. Answer: a bow down trim due just to the added weight being perfectly placed over the old trim CofB/CofM position. So much to consider. Rather than lifting the loaded kayak up to balance it why not just bring a small level with you and once you've gotten into the floating kayak check that the kayak is now level (or slightly stern heavy if loaded with gear or the kayak has a weather helm tendency--my recommendation). A small level is so much easier to lift than a loaded kayak and when the kayak is floating with you in it all of the confoundings that can mess up your system get accounted for as well. > You are correct that a kayak balanced when moving forward will blow at some > angle downwind (where the forces balance) if it is not moving forward. First > you are not talking of a huge difference due to different wind speeds (or > over normal paddling speed ranges) and secondly you have things backwards at > higher speeds. "Wind puts more pressure on the end of a long symmetrical object angled into the wind than one angled away." >>Hmmm. Think of this: Place a brick at 45 degrees in a wind tunnel, with the long side of the brick across the windstream. Mark one end of the brick "A", and the other "B". Look across the brick from end "A", and then again from end "B". Did the wind pressure on the brick change when you changed your viewpoint?<< Huh? Is this brick free to pivot or is it locked into place by friction or in some other way? If the wind is blowing such that it hits end "A" first that end will have more pressure on it than end "B". If the brick is like a floating kayak (free to pivot) it will end up balancing when it is completely sideways to the wind (if it is symmetrical in all respects and suspended from the balance point). What could changing your viewpoint have to do with it? This same effect is working against weathercocking or lee cocking in a kayak and as the wind gets stronger it overpowers the forces causing weather helm and eventually tends to lock the kayak into a sideways orientation (at its balance point--taking into consideration the center of wind force and the center of the hulls lateral resistance in the water at the angle it is traveling at relative to the wind). This is why it can be so hard to turn any long kayak into (or away) from an extremely strong wind. Waves compound the situation further as they also balance out a long object sideways to the waves direction. Bigger waves help some in this situation as they shield you from the winds when you are in the trough. Long waves, like swell, have less effect on the kayak because they are so much longer than the kayak hull and therefore don't combine with gravity and effect both ends of the kayak at the same time (tending to pivot it as gravity pulls it down into the troughs) >>And, we are taking a beam wind as the example here, which I think of as being the maximum weathercocking situation, and not having the kayak angled into the wind or away from it.<< The kayak turns into the wind as it weathercocks so you are soon not in a pure beam wind situation anymore. Absent any counteractions on the part of the paddler this continues until a balance is reached with the force acting more strongly on the end of the kayak pointed into the wind than on the other end. If this was not so wouldn't the kayak keep turning until it pointed directly up wind due to the weather cocking effect. The imbalance between the center of windage and the center of lateral resistance is finally resolved at some angle and that becomes a course that is easy to maintain (if no significant wave effects intrude). "Strong winds ... tend to reduce both weather helm and lee helm." >>Interesting. The worst weather helm experienced is on flat water, such as when wind blows offshore, with very short fetch over low land.<< True, see the effect of waves described above (which are not acting in this situation). >>Weather helm appears to me to worsen as the wind increases in these situations. In other higher wind situations, when the water is rough, the weather helm effect is hard to distinguish from the push and shove of waves, and wind on the bow at the crest, etc. Although all the forces on the boat are greater in higher winds, you would expect, from say a vector diagram analysis of the weather helm effect, that the weather helm effect rises too. Isn't it just that it is masked by other greater forces relatively? Cheers, PT<< Overwhelmed rather than masked would be more like it (because they are working against each other rather than in concert where the overwhelming strength of one might mask the other rather that counteract it). What kayak do you paddle? A fish-form kayak moves its center of lateral resistance further forward than a Swede-form one does as they push through the water. This leaves a longer stern (relative to the center of lateral resistance) to be acted on by the wind. Take it to the extreme by putting the paddler at the (blunt--to maintain level trim) end of each kayak and it should be obvious what is happening. Other things being equal fish-form kayaks weather helm more than Swede-form ones. When sitting still in a side wind does your kayak blow straight sideways or slightly bow or stern down wind? The reason I ask is that this may explain why our experiences differ as to what wind speeds make for the worst weather helm with the kayaks we paddle. It would seem likely that a kayak with a strong weather helm would take a higher side wind blowing (with greater pressure on the end most towards the wind) to overcome the stronger weathercocking effect. I discriminate against strongly weather helming kayaks so don't paddle them as much as those that have a much more controllable (closer to neutral) weather balance. Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Michael Daly <mikedaly_at_magma.ca> wrote:>> << <Snip> >>I've been thinking of this on the weekend - if we rely on weight distribution to minimize need for a skeg/rudder, we risk goofing and not being able to adjust on the water. If we rig a sliding seat to correct on the fly, we have simply replaced one form of mechanism that can fail with another.<< While any mechanism might fail some have proven a lot more reliable than others. A few posts back I listed every minor failure I knew about with our sliding seat system. I'll add that it might take a new paddler a little while to learn how to move it (especially if they have not gotten any instruction). Someone with experience doesn't have to even slow the kayak down but can move it with, at most, the loss of a stroke or two. How many failures with sliding seats have you seen? I realize Mariner sliding seats are much less numerous than kayaks with skegs but my experience is that even including the half dozen or so minor slide bolt failures (that don't have much immediate effect on function--the sliding seat is still useable but the pedal isn't held up as high as it should be) failures have happened to far less than 1% of the owners (even just once) in the last 23 years since we started making them. What is the "Subject" line of this discussion? Considering that many skeg owners have had multiple problems and repeated jams with the same skeg and most have jammed their skeg at least once, the "failure rate" of skegs must be well over 100% (possibly as much as 500% or more). I'll bet the percentage of skeg users that have had extremely serious and difficult to repair problems (such as skeg box leaks flooding their stern compartment) is well over 1%. I'm sure some companies skegs are a lot more reliable than others so I don't mean this as a blanket indictment of skegs. In general I'd prefer a problem free skeg to a problem free rudder. For the most part though, it seems that there is a lot of room for improvement with skeg systems. >>Given the simplicity of the most basic skeg designs (rope and cleat rather than silly little sliders and Bowden cables), I don't see much point in avoiding them. The skeg box's blockage of the stern storage area is a minor annoyance IMHO. << Mike<< >>BTW, Nimbus (Rainforest Designs) kayaks all have sliding seats.<< Nimbus seats can be adjusted fore and aft. They have recently made it a lot easier than it was previously (formerly required tools while out of the seat on shore). With the latest version it is possible to move the Nimbus seat while sitting in it although it does require readjusting 4 to 6 webbing straps (four on the seat bottom and two for the foot pedals) and the backrest cord, This is not something that can be done in an instant to optimize the performance for a particular short term condition but adjustment might well be considered if that condition was expected to prevail for a long time. Since most have a rudder, the rudder can be used for short term corrections without much loss. Disclaimer: we sell Nimbus kayaks in our store. Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Personally, zero. While the sliding seat is an ingenious engineering idea for me it ruins the purity of the boat. Sorry Matt, but I would never own one. We bought our Express and Elan to avoid having any mechanisms to fail or adjustable gizmos to distract from paddling. I even threw out the contoured foam pad that came with the boats. I glued a one inch thick mini-cell foam pad to the hull so that comes right up the sides at the hips and is long enough (for/aft) to allow any reasonable seating position. My maximum position forward it set by the foot braces and the maximum rearward position by the seat back. Primary positioning is by the foot braces though, so it's repeatable. I've got an inch or two of "trim" just by how I position myself in the boat and that's enough. It took 4 or 5 paddles to get it optimally adjusted, but now it's done. It allows some movement, but is still plenty tight for surfing, bracing, rolling, etc. The boats track and turn wonderfully with the simple foam pads I have glued to the hull. Overall they work far better than any rudder or drop skeg boat I have paddled. Do they track perfectly in all conditions? No, but minor edging takes care of the rest. They just don't need "fixing" with a complex seat. I'll admit that we haven't paddled the boats loaded yet, but we have been able to balance other boats while packing a full load without using whatever gizmos the boats had for tracking. I am confident we can do the same for the Mariners. There will be some trial and error and even then it won't be perfect, but that's one of the reasons I go on multi-day kayaking trips rather than ocean liner cruises. Steve Brown -----Original Message----- ............ A few posts back I listed every minor failure I knew about with our sliding seat system. I'll add that it might take a new paddler a little while to learn how to move it (especially if they have not gotten any instruction). Someone with experience doesn't have to even slow the kayak down but can move it with, at most, the loss of a stroke or two. How many failures with sliding seats have you seen? ............ Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Once, in surf, I witnessed a very competent paddler and Mariner fan slide so far forward in his 'sliding seat' that his skirt blew off the back of the rim and he was as deep into the front of the boat as possible. Literally up to his armpits. He wasn't very happy. I personally wouldn't want my seat shifting around, fore and aft, while underway. steve Alder Creek Kayak & Canoe N 45: 36.285' 250 NE Tomahawk Isle Dr. W 122: 39.841' Portland, OR 97217 Web: www.aldercreek.com Phone: 503.285.0464 Email: aldercreek_at_qwest.net *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Steve from "Alder Creek Kayak & Canoe" <aldercreek_at_qwest.net> and the reported designer of WS Tempest series (kayaks with skegs) wrote: >>>>>>>Once, in surf, I witnessed a very competent paddler and Mariner fan slide so far forward in his 'sliding seat' that his skirt blew off the back of the rim and he was as deep into the front of the boat as possible. Literally up to his armpits. He wasn't very happy. I personally wouldn't want my seat shifting around, fore and aft, while underway.<<<<<<< Steve, could you tell me this paddlers name as I would like to talk to him about this incident? If you don't have that information could you tell me the model and color of his kayak? He would be the first person I am aware of to have this happen and I would like to know more details about it. Could you also tell me how he recovered from this situation? I have done many enders (forward and backwards) in the surf with sliding seats and never had the seat move to any appreciable degree but we are well aware (as surf kayakers before since we first designed it) that it might be possible to have the seat slide forward in the surf under just the right combination of conditions. The one I can imagine would be due to an ender in shallow water where the fast moving bow speared the bottom at a shallow enough angle so that it didn't force the kayak into an immediate ender but rather stopped it cold. One of the reasons for the raked bow shape on our designs is to prevent the bow from stopping suddenly if it contacts the bottom at a shallow angle (or any hard object in the water head on). This is not just to help keep the seat from sliding forward but such a collision could be very hard on ones ankles, the kayak's foot pedals, and the kayak using just about any kayak with footbraces. I learned about this possibility early in my kayaking career when using old pointed bow (1970's vintage) whitewater kayaks in the surf before I even owned a sea kayak. Several times in various kayaks I've had the bow snag the bottom and result in an ender in shallow surf. More often the bow has bounced off the bottom, hopping forward in sort of a stutter step, but I have yet to snag the bow in a Mariner model. In fact, I don't recall ever having a Mariner model pearl that deep (except doing a rear ender--I have a slide of one where all that is visible is the very bow of the 16' 6" long Escape and one paddle blade sticking out of the wave--I wish it had been a motor drive or video camera as the next thing I knew Cam was completely vertical and airborne in what looked like a Polaris missile rising from the surface and I missed the shot). Only a few times have I ever been able to get the bow of Coaster or Express to pearl at all in big surf even though I was trying to do so (and those times their bow's quickly rose back to the surface rather than diving towards the bottom). I once accidentally ran straight into a shore consisting of big boulders of sharp edged volcanic rubble paddling at a racing speed. Imagine river rip-rap to get an idea of the shore's steepness and boulder size. My Mariner II was suspended over the water with my bow three feet in the air and the stern still in the water. The sliding seat didn't move but I was feeling like a turkey on a spit. Feeling very tippy and having a heck of a time reaching down to the water to brace. Luckily, I slid backwards down into the water again without capsizing. It was a pitch black moonless cloudy Baja night and I was fascinated by the patterns of vortices swirling around my paddle blade (made visible by the brightest phosphorescence I had ever seen--which also didn't help my night vision). I had paddled faster and faster to see how the swirl patterns might change with speed (in a direction I had thought was toward open water until the moment I felt and heard the initial crash). The kayak is still my demo Mariner II, some gouges near the bow serve to remind me of that folly. Had I first hit the bow square into a big boulder the seat might have moved and my ankles would have been very thankful if it did. As it was the rake at the bow bounced it up higher and higher as it glanced off the boulders. The sliding seat footbraces are also designed to bind up temporarily (like brakes) and not allow the seat to slide much if sudden pressure is applied to them anywhere but with just the outside of the foot to just the hull-most part of the pedal. This makes teaching someone to slide the seat a little more difficult at first but helps prevent sudden major unwanted seat slides in a collision. While I can see how the seat might slide forward given just the right combination of factors (including just the right position of the feet on the pedals) I'm having a hard time seeing how someone could get "up to his armpits" in the cockpit of any kayak unless their feet somehow slid past the foot pedals. Feet sliding past the pedals would seem a lot less likely to happen if the seat/footbrace unit slid forward some softening the blow of spearing the bottom. Maybe the paddler you say had this experience can fill in the details for us. Below are some quotes copied from the Mariner "Owners" manual (the full version is available on our website) that address the possibility of having the seat get too far forward. "After you've acquired the technique of moving the seat back and forward practice sliding the seat back when capsized and hanging upside down in the cockpit because wet exiting will be more difficult if the seat is well forward of trim, especially for very large paddlers. When you first try this have a friend standing by to help you back upright if necessary." Later in the manual the entrapment issue (from many possible causes) is addressed in detail (and in boldface). The part concerning the issue with the sliding seat you are concerned about is below: "MORE SAFETY CAUTIONS AND WARNINGS <Big Snip> Although it has never happened to us (or any other surf kayakers we knew) during many years of surfing with our sliding seat kayaks, there is still the possibility that when paddling in bigger surf (or rock gardens and sea caves combined with ocean swell) that the kayak's bow could hit the bottom (or a solid object) hard enough that the seat might be moved well forward (even though the seat won't move forward easily unless several things are done in just the right combination). While we have always found the sliding seat to be especially easy to move to the back when we were upside down, if something were to block the seat's free movement to the rear (once it had been moved well forward) then it could conceivably be difficult to exit the cockpit. We strongly suggest you also practice sliding the seat while upside down. Do this in shallow water with a friend standing by to help should you have trouble. Remember to take the pressure off your feet anytime you want to move the seat backwards. With the possibility of entrapment in mind, we suggest that anyone intending to paddle in extreme conditions (while using the sliding seat option), both make sure to not put anything behind the seat that could shift around and block it from moving freely backwards and to limit the forward slide range of the seat to a point where a wet exit would still be easy. The easiest way we have found to limit the seats slide range is by drilling holes through the cockpit coaming's (hung seat) hangers and through both of the seatbacks vertical braces (near the seat body and top of the braces) such that a stout 1/4 or 5/16 inch nylon cord can be threaded through all four holes in a relatively straight line. Next adjust the stout cord's length to limit the range of the seat to positions where wet exits are easy for you. The cord can be removed or loosened some for less extreme paddling and the full seat slide range restored." Matt Broze www.marinerkayaks.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
At 10:39 PM 7/6/2004 -0700, Matt Broze wrote: > One of the reasons for the raked bow shape on our >designs is to prevent the bow from stopping suddenly if it contacts the >bottom at a shallow angle (or any hard object in the water head on). This is >not just to help keep the seat from sliding forward but such a collision >could be very hard on ones ankles, the kayak's foot pedals, and the kayak >using just about any kayak with footbraces. I read somewhere that one of the traditional reasons for a raked bow on a kayak was to allow hunters to paddle up onto an ice flow (seal landing) rather than have the bow possibly go under the ice when making contact. *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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