First off, I don't like Nick's suggestion that the position of the inflection point is a good metric for comparing the relative stability between different kayaks. I think a kayak with the most secondary stability has a peak that occurs with the most amount of kayak tilt. In other words, the further to the "right" is the peak, the more stable is the kayak. But the force vs. tilt angle curves are somewhat misleading anyway because they ignore the essential physics of a boat-paddler combination. This has undoubtedly led to some of the challenge in discussing the issue... (I'll keep my theories secret on the origin of the rest... hehee :) Let's get back to the basic physics of staying upright. It's simple, right? If the center of gravity of the paddler is directly above the center of bouyancy of the boat, the boat-paddler system remains upright and dry. If the paddler tilts the kayak, which shifts his CG to the side, then the CB of the boat must also shift by the same amount, or else a capsize occurs. What happens when a paddler-kayak system is tilted: CG: For low angles of edge, the CG will essentially remain stationary because the paddler compensates by bending his spine ("J-lean") For higher angles of edge, the CG will start to move laterally towards to edge of the kayak due to physiological limitations of the spine. CB: For low angles of edge, I would expect that the CB would move towards the side that is being edged in all cases. As larger angles of edge are applied, the CB may continue to move sideways, but eventualy it will stop moving or even move back towards the center of the boat. It is at the point where the CG stops moving outward that the boat will no longer be stable for increasing amounts of edge. Essentially, this is the limit of secondary stability. Now here's my question... the location of the CB with varying degrees of tilt should be just as easy to calculate as the bouyant resistive force, if not even easier. Why doesn't someone modify a program to measure this? I think it would be a lot easier to quantitatively understand the secondary stability of kayaks by this metric. I guess I'm never one to skip an opportunity to add fuel to the fire... Cheers, Kevin ps. I'm going paddling tomorrow in my brand spanking new Riot Prankster. That's a rodeo boat for big boys (like me)... it's much too cold to paddle anything but rivers these days. *************************************************************************** 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/ ***************************************************************************
Kevin wrote: (SNIP) > > Now here's my question... the location of the CB with varying degrees of > tilt should be just as easy to calculate as the bouyant resistive force, if > not even easier. Why doesn't someone modify a program to measure this? I > think it would be a lot easier to quantitatively understand the secondary > stability of kayaks by this metric. > No need to modify the programs. Most already handle this. In Nautilus one manually alters the transverse and vertical centers of gravity to reflect the changes. The problem with publishing this kind of information comes from the differences between paddlers. The curve produced by a good athletic paddler would not match one produced by me. In any case, the stability curve shapes remain fairly constant (not always so it helps to actually calculate them for better accuracy) and one can just add the righting forces together without resorting to a program and stiull get a good idea of stabilty characteristics. This method reveals the total righting force of the system as well as the force at any given degree of heel. You can add these righting moments as the heel occurs or even add them in a delayed fashion to account for slower reactions. My program can do this and I suspect Nick's MacSurf can do it as well. Having done this and compared my perceptions to the curves it appears valid. Admittedly I have not tried it with a large sample but I suspect that the perception of righting force will remain reasonably consistent. Cheers, John Winters Waveform Plastics Technologies Ltd. 15 Ena Ave. South River, Ontario P0A 1X0 *************************************************************************** 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/ ***************************************************************************
I will be the first to admit to problems with my suggested definition. I tend to agree that the boat with the higher maximum stability will rated the one with the most "secondary" by most people. What I was trying to get at was that feeling some people notice in boats that are not generally considered all that stable. I am also seeking a definition that does not depend on the paddler's skills. With practice, a skilled paddler can keep just about anything upright. A novice paddler may have trouble keeping a bath tub upright. Stability curves are determined assuming a rigid hunk of meat in the cockpit. This has the advantage of being skill independent, any idiot can by a rigid hunk of meat. My suggestion of looking at the inflection point is an attempt to quantify the feel in some boats that they get harder to lean at some point. Maybe this feeling should be called something else: "reserve" stability or something. Nick -- Nick Schade Guillemot Kayaks 824 Thompson St, Suite I Glastonbury, CT 06033 (860) 659-8847 Schade_at_guillemot-kayaks.com http://www.guillemot-kayaks.com/ >>>>"It's not just Art, It's a Craft!"<<<< *************************************************************************** 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/ ***************************************************************************
Nick wrote: (SNIP) > I am also seeking a definition that does not depend on the paddler's > skills. With practice, a skilled paddler can keep just about anything > upright. A novice paddler may have trouble keeping a bath tub > upright. Stability curves are determined assuming a rigid hunk of > meat in the cockpit. This has the advantage of being skill > independent, any idiot can by a rigid hunk of meat. > > My suggestion of looking at the inflection point is an attempt to > quantify the feel in some boats that they get harder to lean at some > point. Maybe this feeling should be called something else: "reserve" > stability or something. What about the rate at which stability changes. It seems that a boat that has a rapid change of stability would fit what some paddler's call "notchy". What could you add to the inflection point location information that would reveal this? I think the slope in combination with the area under the curve has the potential to tell us this. Finding some kind of "number" might prove difficult, however. I recall that the U.S. Navy has a method by which they determine "safe" stability at high (above initial stability) heels. I don't know how that will apply but maybe in some modified form it will. One thought. Suppose you normalize the stability curve (i.e. make it non dimensional by dividing the righting moment at every heel by the maximum) and then compare the curves. It would seem that the boat with the greater area under the curve beyond the initial stability realm would feel like it had the highest stability. One could easily check this if you had access to a lot of paddlers and differing boats. In this way you might see relative rather than absolute values and paddlers seem to like "relative". John Winters Waveform Plastics Technologies Ltd. 15 Ena Ave. South River, Ontario P0A 1X0 *************************************************************************** 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/ ***************************************************************************
Can you try to give an example of what you mean by "notchy" just so we are on the same page here. In my "inflection point" theory I was thinking of looking at the slope of the curve at the inflection point for some reading on the relative "secondary" stability. Looking at how quickly the slope of the curve changes would probably help indicate how noticeable the stiffening is. My example: http://www.guillemot-kayaks.com/Example.gif would have a quite noticeable point where it feels like it is getting more stable. I suppose this could be called notchy. At any point on the curve you have several things that may be interesting to look at: The righting moment - just how much force is being applied to right the boat; the area under the curve - how much energy it took to get the boat to that point; the slope of the curve - how hard it will be to tip it farther; and I am adding: the rate of change of the slope of the curve - the trend of how hard it is to tip the boat farther. i.e getting easier or getting harder to tip a little farther. "notchiness" sounds to me like: The rate of change of the rate of change of the slope of the curve (follow that?) - or how quickly the trend of how-hard-it-is-to-tip-farther changes. While this is quantifiable, I am not sure how important it is. By this definition a "notchy" boat might be able to tip fairly easily until a point where it suddenly becomes hard to tip farther, but if you do it quickly becomes easy again. And the notchiness is the suddenness of the change. Worded that way it sounds interesting - this feeling would be quantified by a relatively high value of the 3rd derivative. And that is why I don't really feel comfortable with it. What is the 3rd derivative really. If the stability curve corresponds to a plot of distance a car travels from home over time, the first derivative is the velocity of the car. The 2nd derivative is the acceleration of the car which pushes you back in your seat. I suppose the 3rd derivative corresponds to that funny feeling you get when go over a hump in the road while going fast and you stomach does a little back flip. I think there may be some merit to the idea of normalizing the curves to the maximum stability. Like you suggest it would help identify boats which have "good secondary" relative to their overall stability. Nick At 8:37 AM -0500 11/20/00, 735769 wrote: >Nick wrote: > >(SNIP) > >> I am also seeking a definition that does not depend on the paddler's >> skills. With practice, a skilled paddler can keep just about anything >> upright. A novice paddler may have trouble keeping a bath tub >> upright. Stability curves are determined assuming a rigid hunk of >> meat in the cockpit. This has the advantage of being skill >> independent, any idiot can by a rigid hunk of meat. >> >> My suggestion of looking at the inflection point is an attempt to >> quantify the feel in some boats that they get harder to lean at some >> point. Maybe this feeling should be called something else: "reserve" >> stability or something. > >What about the rate at which stability changes. It seems that a boat that >has a rapid change of stability would fit what some paddler's call "notchy". >What could you add to the inflection point location information that would >reveal this? > >I think the slope in combination with the area under the curve has the >potential to tell us this. Finding some kind of "number" might prove >difficult, however. I recall that the U.S. Navy has a method by which they >determine "safe" stability at high (above initial stability) heels. I don't >know how that will apply but maybe in some modified form it will. > >One thought. Suppose you normalize the stability curve (i.e. make it non >dimensional by dividing the righting moment at every heel by the maximum) >and then compare the curves. It would seem that the boat with the greater >area under the curve beyond the initial stability realm would feel like it >had the highest stability. One could easily check this if you had access to >a lot of paddlers and differing boats. In this way you might see relative >rather than absolute values and paddlers seem to like "relative". -- Nick Schade Guillemot Kayaks 824 Thompson St, Suite I Glastonbury, CT 06033 (860) 659-8847 Schade_at_guillemot-kayaks.com http://www.guillemot-kayaks.com/ >>>>"It's not just Art, It's a Craft!"<<<< *************************************************************************** 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/ ***************************************************************************
Nick wrote: (SNIP) > > "notchiness" sounds to me like: The rate of change of the rate of > change of the slope of the curve (follow that?) - or how quickly the > trend of how-hard-it-is-to-tip-farther changes. I see it the same way. The boats that I have heard people describe as "notchy" have curves that show abrubt (OK, how much is abrubt?) changes in curvature both up and down slope. I once paddled a canoe that flopped from side to side at small angles of heel quite easily then got stiffer and then a bit further on just about tossed me out of the boat. Others who paddled it called it notchy. I called it weird. It had a concave curve for the first ten degrees or so (if I remember correctly I no longer have that info or the lines to that boat) rose quickly to its maximum and then dropped just as quickly to the maximum range. Very disconcerting and reminded me of the feel of a sprint canoe. The boat had a steeply "V"ed bottom with a small radius at the turn of the bilge and tumblehome coupled with relatively low freeboard. I wish I had kept the lines. >And the notchiness is the suddenness of the > change. Worded that way it sounds interesting - this feeling would be > quantified by a relatively high value of the 3rd derivative. And that > is why I don't really feel comfortable with it. What is the 3rd > derivative really. Beats me. Never understood that stuff > > I think there may be some merit to the idea of normalizing the curves > to the maximum stability. Like you suggest it would help identify > boats which have "good secondary" relative to their overall stability. I did some last night and it looked interesting but, as an old friend once said, "I don't understand everything I know about that." Unfortunately we now have hard water and I can't test anything. Cheers, John Winters Waveform Plastics Technologies Ltd. 15 Ena Ave. South River, Ontario P0A 1X0 *************************************************************************** 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/ ***************************************************************************
I've been looking at boats again (bad girl!), and a friend of mine just got a Boreal Ellesmere, which appears to be an interesting boat. On their website they describe it has having "inverse hard chines." I'm not sure what that means - could it bear any relation to "notchiness?" Joan On Tue, 21 Nov 2000 08:02:46 -0500 "735769" <735769_at_ican.net> writes: > Nick wrote: > > (SNIP) > > > > > "notchiness" sounds to me like: The rate of change of the rate of > > change of the slope of the curve (follow that?) - or how quickly > the > > trend of how-hard-it-is-to-tip-farther changes. > > I see it the same way. The boats that I have heard people describe as > "notchy" have curves that show abrubt (OK, how much is abrubt?) > changes in > curvature both up and down slope. *************************************************************************** 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/ ***************************************************************************
Joan wrote: >>I've been looking at boats again (bad girl!), and a friend of mine just got a Boreal Ellesmere, which appears to be an interesting boat. On their website they describe it has having "inverse hard chines." I'm not sure what that means - could it bear any relation to "notchiness?" Joan<< Hi Joan, There's a review of the Ellesmere in the Feb. 2000 Sea Kayaker, and there, you can see the "inverse" chines. It's an interesting looking chine arrangement. It has a second, "upper chine" that curves down at either end. It also has a rounded hull instead of a shallow V. I haven't paddled one yet, but I'm very interested in trying it. I have no idea of the "notchiness factor" of this boaty. Melissa *************************************************************************** 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/ ***************************************************************************
Melissa Reese wrote: > > Hi Joan, > > There's a review of the Ellesmere in the Feb. 2000 Sea Kayaker, and > there, you can see the "inverse" chines. It's an interesting looking > chine arrangement. It has a second, "upper chine" that curves down > at either end. It also has a rounded hull instead of a shallow V. I > haven't paddled one yet, but I'm very interested in trying it. I > have no idea of the "notchiness factor" of this boaty. In a sense, the chines on all folding kayaks are "inverse." All folding kayaks, by definition, are hard-chined because of their use of longitudinal stringers running the length of the boats. The inverse factor is apparent if you sit in a folding kayak on the water and look down inside with the clearest example being Feathercrafts. Water pressure pushes up against the skin between between the keel bar and stringers on each side. Looking at just one side, you will see an elongated concave pocket (or convex, depending on how you view it) created between the keel bar and the chine bar and another similar pocket between the chine bar and the gunwale. Now switch to a straight-on profile look at the boat. These concave (or convex) pockets, in effect, invert the chine as they curve inward above and below the chine. That feeling of notchiness that has been described here is nothing new to a folding kayaker. When you tip a foldable to one side, you most definitely feel the notches or inversion of the chines. It is more noticable in slimmer folding kayaks like those from Feathercraft which are easier to dip to one side than broader ones. Also, Feathercraft seems to cut their hulls a bit looser than other manufacturers (or they appear that way) and that makes those concave pockets more pronounced. I see the difference is quite significant when I compare what the pocket appears like in my Nautiraid single as opposed to my Feathercraft K-Light. The indent of the pocket on the Nautiraid is much more shallow than the one of the K-Light. ralph diaz -- ----------------------------------------------------------------------- Ralph Diaz . . . Folding Kayaker newsletter PO Box 0754, New York, NY 10024 Tel: 212-724-5069; E-mail: rdiaz_at_ix.netcom.com "Where's your sea kayak?"----"It's in the bag." ----------------------------------------------------------------------- *************************************************************************** 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/ ***************************************************************************
I'm aware that some people are perhaps a little bored with the stability thread. Well, folks, I'm here to tell you that it could be worse. I'd much rather read barely comprehensible discussions of stability curves than all the s*o*s*n jazz that's erupted again on RBP, and now on RBPT, too. I think I'll give them both a rest for a while. With that thought in mind, I'm wondering if anyone has dates for several events set for next year. I've just checked the websites involved, and they either still have last year's dates up (or worse), or nothing at all. I'm interested in: Quietwater Symposium, Lansing, MI -- late February? Canoecopia, Madison, WI -- early March? Georgian Bay Symposium, Nobel, ON -- mid May? West Michigan Symposium, Muskegon, MI -- Memorial Day weekend? Great Lakes Sea Kayaking Symposium, Grand Marais, MI -- mid July? And a happy Turkey Day to all of you that celebrate it. It'd be nice to go kayaking, but Lake Michigan has come to my driveway, rather than my going to Lake Michigan. -- Wes *************************************************************************** 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/ ***************************************************************************
I can't say much about the chines and such but i can contest to Boreal boats I love mine and have had no problems, they are a great company and really friendly to deal with. I also own a boreal paddle. Kate *************************************************************************** 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/ ***************************************************************************
ralph diaz <rdiaz_at_ix.netcom.com> wrote: >>>>>Melissa Reese wrote: > > Hi Joan, > > There's a review of the Ellesmere in the Feb. 2000 Sea Kayaker, and > there, you can see the "inverse" chines. It's an interesting looking > chine arrangement. It has a second, "upper chine" that curves down > at either end. It also has a rounded hull instead of a shallow V. I > haven't paddled one yet, but I'm very interested in trying it. I > have no idea of the "notchiness factor" of this boaty. In a sense, the chines on all folding kayaks are "inverse." All folding kayaks, by definition, are hard-chined because of their use of longitudinal stringers running the length of the boats.<<<<SNIP> This is not what Boreal means. They essentially took a more rounded hull and cut flat slabs off each side. Ralph is talking about the inversion between the stringers (longerons?) due to water pressure on a folding kayak. Totally different thing. I paddled an Ellsmere both at the 1999 West Coast Symposium two years ago and again later at my shop. It is not notchy due to the chine or any other (more likely) reasons. I thought it was a sporty fun kayak that turned well with a lean and was relatively easy to lean but not tippy. Good secondary stability too:-) My notes say I could spin 360 degrees in 23 sec. leaned (to the outside) and in 27 seconds with the hull level. I could turn 180 degrees (at speed while leaned out to the risk point) in 11 sec. and the 180 turn took 18 seconds if I didn't lean at all (a measure of tracking stiffness). Averages of 305 N.Amer. kayaks I tested are 11 seconds for the 180 degree leaned turn and 20 sec. for the 180 if level (259 kayaks for this average)(Note: the averages include a lot of short recreational kayaks which skews the averages down a little--the average N. A. made kayak (of 864 which I have lengths on) is 14 foot 10.5 inches long and 24.9" wide and the Ellsemere is 17-0 long. The Ellesmere took me 24 sec. with the skeg down full to spin a 360 with a lean, 30 sec. level, 26 sec. 180 leaned turn w/skeg max. down, and 66 sec. with max. skeg if held level). Without the skeg down the kayak had a strong weatherhelm which the skeg corrected. The shaped skeg hummed when down. Something I've noticed with a lot of shaped skegs but not with flat skegs (which unfortunately create more drag). Sea Kayaker tested it in their Feb. 2000 issue. This review is not on their website, I checked. I just read the review on paper and while I didn't test the Ellesmere in waves or surf and I didn't roll it I agreed with the testers on all the other points so I suspect I would agree with them on those as well. I too barked my knuckles on the skeg adjustment cleat, hope they have moved it to a better location (or better still changed the whole skeg arrangement) by now. Matt Broze http://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 09:54 PM 11/22/00 -0800, Matt Broze wrote: >stability too:-) My notes say I could spin 360 degrees in 23 sec. leaned (to >the outside) and in 27 seconds with the hull level. I could turn 180 degrees >(at speed while leaned out to the risk point) in 11 sec. and the 180 turn >took 18 seconds if I didn't lean at all (a measure of tracking stiffness). >Averages of 305 N.Amer. kayaks I tested are 11 seconds for the 180 degree >leaned turn and 20 sec. for the 180 if level (259 kayaks for this (snip of more data) OK, let's move on to lateral stability now that everyone's eyes are glazed. This peek we were just given into your notebooks is fascinating. For years, I've been of the opinion that the boats that I normally paddle are very stiff tracking, yet the numbers you present here aren't that out of line with what I'm used to. Because of my size, I don't get to paddle a lot of smaller kayaks, but I've been of the opinion that my size adds to the stiff tracking. My Nimbus Telkwa is a slow turner, although I've never timed it the way you have. In fact, I suspect it turns faster with the rudder up than it does with the rudder down. (The rudder is nice to have in crosswinds, though.) Again, I suspect that my fat butt has something to do with the slow turning times. Earlier this month, I paddled a whitewater boat that was large enough to fit me -- an older Prijon T-Canyon -- and I can't believe it would have taken more than two seconds to do a 180 level and sitting. We're talking turning on a dime and giving back nine cents change. Needless to say, it was not the most pleasant boat to paddle on flatwater that I've ever seen. So, I guess I'm saying that sea kayaks in general tend to all be pretty stiff tracking. What, in your subjective opinion, is a good balance between tracking and turning for a touring boat? A surfing kayak? What do you do to get the best of both worlds? I suppose that this is one of those things where everyone has an opinion. I'd be interested in seeing a few of your figures for turn times for selected examples of various popular boats, to see how they compare. -- Wes *************************************************************************** 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/ ***************************************************************************
Wes Boyd <boydwe_at_dmci.net> wrote: >>>>>>>At 09:54 PM 11/22/00 -0800, Matt Broze wrote: >stability too:-) My notes say I could spin 360 degrees in 23 sec. leaned (to >the outside) and in 27 seconds with the hull level. I could turn 180 degrees >(at speed while leaned out to the risk point) in 11 sec. and the 180 turn >took 18 seconds if I didn't lean at all (a measure of tracking stiffness). >Averages of 305 N.Amer. kayaks I tested are 11 seconds for the 180 degree >leaned turn and 20 sec. for the 180 if level (259 kayaks for this (snip of more data) OK, let's move on to lateral stability now that everyone's eyes are glazed. This peek we were just given into your notebooks is fascinating. For years, I've been of the opinion that the boats that I normally paddle are very stiff tracking, yet the numbers you present here aren't that out of line with what I'm used to. Because of my size, I don't get to paddle a lot of smaller kayaks, but I've been of the opinion that my size adds to the stiff tracking.<<<<<< Because you are heavier you sink the keels deeper and that probably makes the kayaker harder to turn and your extra strength won't help make it all up >>>>>>My Nimbus Telkwa is a slow turner, although I've never timed it the way you have. In fact, I suspect it turns faster with the rudder up than it does with the rudder down. (The rudder is nice to have in crosswinds, though.) Again, I suspect that my fat butt has something to do with the slow turning times.<<<<<< Actually the Telkwa is only a stiff tracker/slow turner if you don't lean it strongly. It is an amazingly maneuverable kayak for being over 18' long if you are willing to lean strongly. In fact the Std. Telkwa had the biggest percentage spread between how quick I could turn it 180 degrees leaned vs. how quick I could turn it level. 9 sec vs. 28 sec. 8/23 for the HV for me and 10/29 for the Telkwa Sport. Next time you paddle it Wes time how fast you can turn it and spin it in place both leaned and holding it level thoughout. Send us or me the results. Do you have the Std. or HV? BTW it took me 12 sec. with the rudder down and turned fully compared to 9 seconds without. Usually the rudder is a second slower or the same. The Telkwa rudder probably can't be angled as much as some others. Still 12 seconds is a pretty much average turning time for a North American sea kayak and fast for a 18 footer. 360 degree spin in place times were 22 sec. leaned, 29 sec. leaned with rudder, and 27 sec. level. Being heavier your times for level measures will probably be slower. You should still be able (with practice) to learn to turn with a strong lean close to as much faster than your level time as I could do under my level time. The fact that you sink the kayak deeper will limit your lean angle where the cockpit goes under. If you have a spraydeck on you could lean it as much as I do. BTW I weight 190 pounds. >>>>>>Earlier this month, I paddled a whitewater boat that was large enough to fit me -- an older Prijon T-Canyon -- and I can't believe it would have taken more than two seconds to do a 180 level and sitting. We're talking turning on a dime and giving back nine cents change. Needless to say, it was not the most pleasant boat to paddle on flatwater that I've ever seen. So, I guess I'm saying that sea kayaks in general tend to all be pretty stiff tracking. What, in your subjective opinion, is a good balance between tracking and turning for a touring boat? A surfing kayak? What do you do to get the best of both worlds? <<<<<<< I like to see tracking level be at least twice as slow as one can turn it leaned to the point water might splash (but not pour) into the cockpit. All strokes are broad strong forward sweep strokes on one side and the turn is started at cruising speed. Shorter boats will turn much quicker than long ones (in general) but a level turn (tracking) time can be lower in a shorter kayak and it will feel like it tracks fine where the long kayak with the same tracking number might feel squirrelly. Personally I want enough tracking so I don't have to pay any attention to tracking on calm water (and not have to fight strong tendencies in wind and waves). After that I'd try to make the kayak turn as quickly as possible. since leaning lowers turning times I try to enhance the leaned turn. When packing a heavy gear load I like a little stiffer tracking kayak than when paddling one empty because the extra mass in the ends can make a yaw harder to stop then. For surf maneuverability is a real plus. How do we try to get the best of both? Well, there are some things we keep to ourselves. >>>>>>>.I suppose that this is one of those things where everyone has an opinion. I'd be interested in seeing a few of your figures for turn times for selected examples of various popular boats, to see how they compare.<<<<< - -- Wes Someday I might put the whole thing on the web but it probably won't happen until after I retire. Right now you can find the numbers for our all Mariner kayaks about 3/4 of the way through the paddling manual on our website. We put them there to give our customers some times to shoot for in an effort to get them to become better and safer paddlers. Matt Broze http://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 03:40 AM 11/25/00 -0800, you wrote: >Actually the Telkwa is only a stiff tracker/slow turner if you don't lean it >strongly. It is an amazingly maneuverable kayak for being over 18' long if >you are willing to lean strongly. In fact the Std. Telkwa had the biggest >percentage spread between how quick I could turn it 180 degrees leaned vs. >how quick I could turn it level. 9 sec vs. 28 sec. 8/23 for the HV for me >and 10/29 for the Telkwa Sport. I know it turns faster in a leaned turn, but hadn't realized that it was hugely faster. Probably I'm not aggressive enough in the lean. Something to work on, I guess. >Next time you paddle it Wes time how fast you can turn it and spin it in >place both leaned and holding it level thoughout. Send us or me the results. Won't be till spring, now -- the water around here has pretty much turned hard, and I don't feel like being that aggressive in water that's just above freezing, if it's liquid at all. >Do you have the Std. or HV? BTW it took me 12 sec. with the rudder down and >turned fully compared to 9 seconds without. Usually the rudder is a second Sure puts a different light on the rudder vs. no rudder controversy, doesn't it. >slower or the same. The Telkwa rudder probably can't be angled as much as The rudder will turn enough to stall it if you're moving at speed. BTW, I have the standard Telkwa -- the HV felt way too big for me, while the standard was just marginally too big. For a guy my size, having a boat that feels too big is rather unprecedented, and kind of nice. >some others. Still 12 seconds is a pretty much average turning time for a >North American sea kayak and fast for a 18 footer. 360 degree spin in place >times were 22 sec. leaned, 29 sec. leaned with rudder, and 27 sec. level. >Being heavier your times for level measures will probably be slower. You >should still be able (with practice) to learn to turn with a strong lean >close to as much faster than your level time as I could do under my level >time. The fact that you sink the kayak deeper will limit your lean angle >where the cockpit goes under. If you have a spraydeck on you could lean it >as much as I do. BTW I weight 190 pounds. As I said, something to work on when the water is warmer. > >Someday I might put the whole thing on the web but it probably won't happen >until after I retire. Right now you can find the numbers for our all Mariner >kayaks about 3/4 of the way through the paddling manual on our website. We >put them there to give our customers some times to shoot for in an effort to >get them to become better and safer paddlers. The glimpse into those times that you've given us -- after all, all by the same tester does level out some variables -- has given me a new perceptive on turning vs. tracking. Thanks much! -- Wes *************************************************************************** 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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