Fellow paddlers, Since I am new on this mailinglist, allow me to introduce myself before getting down to business. NAME: Niels Blaauw CONTACT: nblaauwboasfoxborodotcom Live and work in the Netherlands KAYAKS: - A Vroom & Dreesman Inflatable (exploded three years ago) - A Pouch double foldable (sold one year ago) - An Old Town Loon 120, an incredibly comfortable boat for swimming, sun bathing and just hanging out; - A Pyranha Magic Bat for fooling around; - A ruddered Prijon Seayak for seakayakking and camping. SPECIALIST KNOWLEGDE: Sewing kayak clothing in windblock- and stretchfleece, adapting plastic kayaks for somebody my length (2 meters) MOST INTERESTING TRIP: Solo camping on the Swedish lakes and Skagerrak. STRONG OPINIONS: - Plastic is the best material to build any kind of kayak. - Rudders are OK. - Cellphones should be switched OFF at all times. - If you are in a hurry to get somewhere, don't take a kayak. Use a car. - It may be dangerous to paddle alone, but to me it is well worth the risk. There is a certain magic, especially in remote places in rain, fog or darkness, that I can't experience with people around me. BIO: I am 37 years old, single, living in the Netherlands, paddling since I was 10 years old but mostly in inflatable or foldable bathtubs. Two years ago I bought the first kayak that deserves the name. By now I have turned into a swimmingpool-fool: At last count I had 11 ways to roll my boat, including one that keeps a burning sigarette or camera above the water. Did some sea, surf and white water kayakking, but my main interest is in solo wilderness camping: Not paddling great distances but just enjoying the beauty of places, entering every bay, climbing every rock and only paddling at a serious speed when I get cold, bored or hungry. I write a column in "Kanosport", the main Dutch kayakking magazine. Most of my writings are fictionous, totally unbelievable travel reports. In my imagination I love paddling with the Tsunami Rangers or Doug Lloyd, but reality is different: I don't have an ocean at my doorstep, which is a good thing since I am too chicken anyway. Dancing is my main excercise, apart from kayakking. Nice to meet you all. ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- ----- Let me get to the point: I paddle a Prijon Seayak, mostly alone but also with other people, who are mostly paddling Romany, North Shore or P&H boats. I got the distinct impression that all boats around me have a higher cruising speed than mine, although it is possible that I am just not motivated to paddle long distances at high speed. I am planning to put the efficiency of my boat to the test, in a scientific way. My idea is to gather a handful of different kayaks and test them one by one, by putting a weight in the seat, towing them behind a motorboat at different speeds, and measuring the force needed to tow the kayak at each speed. I can use a GPS to control the speed. A device to measure force is cheap enough to buy just for the occasion. My questions are: - Did anybody ever perform such a test and if so, what were the results. I am specifically interested in performance of the Seayak, but also in general differences in hull design, boat length and hull material; - I need some people, in the Netherlands, to supply me with a motorboat and as many kayaks as possible, and to join me in a day of playing around with boats. For ideal test conditions we need flat water and little or no wind, so it could result in a lot of fun on a sunny summer day. Anybody interested? Niels Blaauw, the Netherlands. *************************************************************************** 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/ ***************************************************************************
"Blaauw, Niels" <nblaauw_at_foxboro.com> wrote: <SNIP>>>>>>>I am planning to put the efficiency of my boat to the test, in a scientific way. My idea is to gather a handful of different kayaks and test them one by one, by putting a weight in the seat, towing them behind a motorboat at different speeds, and measuring the force needed to tow the kayak at each speed. I can use a GPS to control the speed. A device to measure force is cheap enough to buy just for the occasion. My questions are: - - Did anybody ever perform such a test and if so, what were the results. I am specifically interested in performance of the Seayak, but also in general differences in hull design, boat length and hull material;<<<<<<SNIP> In the mid to late seventies I started testing the top speed of kayaks over a short course (next to a floating bridge out of the wind). Pushing as fast as I could go for about a minute my times for the same kayak was very consistent. This is a good way to test kayaks you want to use for racing, but it won't tell you much about the kayak's efficiency at cruising speed (the important parameter for a sea kayak). The first method I thought might work for testing drag was to get a bunch of different kayak owners to meet at a river bridge and then have one paddler (to keep the weight of "cargo" the same) hold a low speed (tube type) speed meter over the side of the kayak (to test that the current had remained constant). He would remove the knotmeter from the water and others on the bridge would read a surveyor's scale fixed to a point on the bridge with a line or wire to the kayak while he sat in the kayak and held still. The water speed in the same place on the river was expected to stay fairly constant and we would have the knotmeter to check if it changed over time. I kept a lookout for suitable bridges but we never did do this so I don't know how well it would work in reality. Of course, even if worked well it might be difficult to get results at different kayaking speeds. Back in the mid 80's when John Dowd the editor of Sea Kayaker magazine wanted to do kayak testing in a very scientific way we tried to come up with ways to test the drag of kayaks in a simple inexpensive way. Because I had already been thinking about simple and cheap ways to do this since my brother and I first started sea kayaking I already had a few ideas how it might be done and tried to help out. Other ways we thought of back then were towing by a boat, but I wondered if the boat speed could be held constant enough. One way to compare kayaks directly would be to set up a balance beam to tow both kayaks at once and see which one drags back. Then switch sides to confirm the results. A set of "standard" kayaks (or a shape that could be altered in a consistent way) could be developed and tested against the new kayak to find its place in the hierarchy. The advantage would be that the knotmeter would not have to be really accurate or even consistent. The disadvantage would be the number of test runs required (lots of powerboat time). At that time I started to work on a way to run a knotmeter, clock, and a scale (or strain gauge) through an analog/digital converter and into a small computer (these functions are all integrated today and the devices can be quite inexpensive --just a few hundred dollars). Before I really got going on this Sea Kayaker got a special research rate on ship model testing time at the University of B.C. test tank and I dropped my efforts. Now what I would like to do is install strain gauges on a paddle shaft and run that data along with knotmeter data into analog/digital converter/computer device. I think something like this would be the best way to test and compare kayaks (using the same paddler--or rotational sensors as well) because, as opposed to a tow, yawing effects (due to the offside paddle strokes) that probably differ with kayaks would also be accounted for. If somebody wants to do this, contact me and I can save you some effort by telling you what I have already found out about how this might be done. The Prijon Seayak is one of the kayaks Sea Kayaker reviewed and I have run through the mathematical programs that we (John Winters and I) devised to estimate drag. Here are the results from John's estimating method for the kayaks reviewed that you may have access to. The numbers range from drag in pounds at 1.5 knots to 6 knots in 1/2 knot increments. I hope they stay nice and neat in columns (like they were when I send them off into cyberspace). You can download this spreadsheet off our website in the "downloads" section. Keep us informed if you do any testing. Speed in Knots 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 Seayak Rtp (total for plastic) 0.58 0.99 1.51 2.09 3.01 4.36 6.01 8.83 11.96 14.09 Orca by Pyranha Rt (total resistance) 0.54 0.92 1.37 1.92 2.76 3.96 6.04 8.65 11.62 14.53 Yukon Eski (Composite) Rt (total resistance) 0.53 0.91 1.36 1.88 2.61 3.69 5.14 7.65 10.33 12.31 Artisan Millennium (Kayak Sport) Rt (total resistance) 0.54 0.92 1.38 1.92 2.59 3.54 5.11 7.76 10.60 13.81 Avalon Viviane Rt (total resistance) 0.56 0.96 1.44 2.01 2.68 3.53 4.80 7.19 10.26 13.38 Prijon Kodiak Rtp (total for plastic) 0.57 0.97 1.50 2.08 2.82 3.85 5.44 8.11 10.96 14.03 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. 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One method which would be quite easy although not as accurate is to paddle with a heart rate monitor and a speedometer. Try to maintain a constant speed and monitor your heart rate. Higher heart rate -> less efficient. Or try to maintain a constant heart rate and measure distance traveled over a given time. Longer distance -> more efficient. This will have errors due to how fit you are the day you do the test, but it would have the advantage of taking into effect the boat's roll in paddling mechanics. Some kayaks will be harder to paddle due to width, coaming height, seat height etc. The overall efficiency for a given paddler is related to how efficiently he or she can apply power to the water. As long as you use the same paddle this method should measure boat related efficiency. As I said, this method is probably not the most accurate, but the "instruments" are relatively inexpensive and available. A GPS can be used as the speedometer if you are paddling where there is no current. At 12:57 AM -0800 3/8/01, Matt Broze wrote: ><SNIP> > >In the mid to late seventies I started testing the top speed of kayaks over >a short course (next to a floating bridge out of the wind). Pushing as fast >as I could go for about a minute my times for the same kayak was very >consistent. This is a good way to test kayaks you want to use for racing, >but it won't tell you much about the kayak's efficiency at cruising speed >(the important parameter for a sea kayak). <Snip> -- Nick Schade Guillemot Kayaks 824 Thompson St Glastonbury, CT 06033 (860) 659-8847 *************************************************************************** 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/ ***************************************************************************
>>> -----Original Message----- From: owner-paddlewise_at_paddlewise.net [mailto:owner-paddlewise_at_paddlewise.net]On Behalf Of Nick Schade Sent: Thursday, March 08, 2001 9:19 AM To: Paddlewise Subject: Re: [Paddlewise] Hull speed One method which would be quite easy although not as accurate is to paddle with a heart rate monitor and a speedometer. >>> I ride the same 10 or 15 miles every night after work on my bicycle and I maintain the same average pace within 4/10 of a mph over the distance. My heart rate varies significantly, 10 to 15 BPM, with the same speed and conditions depending on what part of the workout and other parameters I'm not aware of. I doubt using a heart monitor would be too meaningful in comparing kayaks. cu *************************************************************************** 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/ ***************************************************************************
--- Bob Denton <BDenton_at_aquagulf.com> wrote: > >>> > -----Original Message----- > From: owner-paddlewise_at_paddlewise.net > [mailto:owner-paddlewise_at_paddlewise.net]On Behalf Of Nick Schade > Sent: Thursday, March 08, 2001 9:19 AM > To: Paddlewise > Subject: Re: [Paddlewise] Hull speed > > > One method which would be quite easy although not as accurate is to > paddle with a heart rate monitor and a speedometer. > >>> > > I ride the same 10 or 15 miles every night after work on my bicycle Wow. That's dedication, or something ;-> When I was a cyclist, I don't think I ever did the same ride twice in one week, except when I was commuting to work. > and I > maintain the same average pace within 4/10 of a mph over the > distance. My > heart rate varies significantly, 10 to 15 BPM, with the same speed > and > conditions depending on what part of the workout and other parameters > I'm > not aware of. Health and fatigue certainly will cause day-to-day variation, but I'll bet that wind and subtle variations in terrain are the big factors here. If you maintain 20 mph, just the difference between a 2 mph headwind and 2 mph tailwind should be enough to explain your variation, but it wouldn't be obvious without the speedometer. At a kayak's speed aero drag in light wind is very little of the total drag, so I would expect wind to be less confounding. At a racing pace, I was surprised to find how strongly I felt changes in the slope of the road that were too small to see readily, often requiring a gear change for an almost-invisible "hill". At a less desperate level of effort, you have more reserve aerobic capacity, and can increase your output a bit without changing gears, often without noticing unless you have a heart monitor or are really paying attention to you effort. Is there a marine analog to this? Boat wakes come to mind. Anyone know if 8 inch/ 20 cm wavelets are significant? If you were to do a couple of back to back runs in dead air and flat water, I'm pretty sure you could see a difference, IF you can maintain a truly constant speed. I've never used a knotmeter, so I don't know how hard that is. Lacking a knotmeter, if I were to try this, I would get warmed up (paddle at least half an hour) then start well back from the measured distance course and try to maintain a stable, moderate heart rate, say 140 bpm, and time a half-mile run, then repeat in the opposite direction, then switch boats. Better yet, bring someone to paddle the other boat along, and do them in order a-b-b-a, hopefully minimizing effects of changing conditions. As Nick pointed out, the big advantage of a live-paddled test is that it might reveal the differences due to ergonomics, which towed tests would not detect. Steering or "tracking" qualities would also be a factor. Subjective ergonomics are also an important area best seen by back to back trials. Mike Wagenbach Seattle Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.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 09:09 AM 3/8/01 -0800, Mike Wagenbach wrote: > Boat wakes come to >mind. Anyone know if 8 inch/ 20 cm wavelets are significant? As you would expect at race pace almost any wave can be significant. Particularly if you are "running" perfectly level, and the waves introduce a bounce (reducing the hull's glide) into the motion. >If you were to do a couple of back to back runs in dead air and flat >water, I'm pretty sure you could see a difference, IF you can maintain >a truly constant speed. I've never used a knotmeter, so I don't know >how hard that is. I used to train on a set course. We would be within 20 seconds on a 30 minute loop consistantly - without a knotmeter. I'm pretty consistant about my paddling rate, based on some of my experiments with an acquaintances boat, which was equiped with a knotmeter. >Lacking a knotmeter, if I were to try this, I would get warmed up >(paddle at least half an hour) then start well back from the measured >distance course and try to maintain a stable, moderate heart rate, say >140 bpm, and time a half-mile run, then repeat in the opposite >direction, then switch boats. Better yet, bring someone to paddle the >other boat along, and do them in order a-b-b-a, hopefully minimizing >effects of changing conditions. I would only do the testing on a lake. I would not do it anywhere with a current and preferably in water at least 10 feet deep - minimizing the effect of the bow wave in relationship to the bottom. kirk *************************************************************************** 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/ ***************************************************************************
As I said, there are limitations to the heart rate monitor, but the amount of work your body does to travel a given distance is the true measure of efficiency of the boat/paddle system and the heart rate monitor is the easiest measure of your body's effort. I suppose it would be nice to know how much oxygen you are burning, but am not aware of any portable, waterproof systems to do it. While your heart rate may change through out a test, the longer the test, the more accurately it will represent the work you are doing. Nick At 10:09 AM -0500 3/8/01, Bob Denton wrote: >One method which would be quite easy although not as accurate is to >paddle with a heart rate monitor and a speedometer. >>>> > >I ride the same 10 or 15 miles every night after work on my bicycle and I >maintain the same average pace within 4/10 of a mph over the distance. My >heart rate varies significantly, 10 to 15 BPM, with the same speed and >conditions depending on what part of the workout and other parameters I'm >not aware of. > >I doubt using a heart monitor would be too meaningful in comparing kayaks. -- Nick Schade Guillemot Kayaks 824 Thompson St Glastonbury, CT 06033 (860) 659-8847 *************************************************************************** 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 live in South Florida and there is really only one safe road to cycle on...A1A. Ironically, it runs parallel to my paddling spots on the beach or intracoastal. There are no hills here and the terrain is almost flat. >> Health and fatigue certainly will cause day-to-day variation, but I'll bet that wind and subtle variations in terrain are the big factors here. >> No, when I first got the heart rate monitor I was interested in seeing improvements in fitness eliminating the other variables as much as possible. The weather this time of year is almost identical on a day to day basis, especially in the evening after work. We have prevailing winds. My average speed is around 18.5 +- .2 mph for a 15 mile circuit with a couple of lights and slow downs. The problem here is trying to neutralize the current and wind factors in the kayak. I used cycling because it the roads don't move relative to the cycle. cya *************************************************************************** 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/ ***************************************************************************
kirk olsen wrote: > At 09:09 AM 3/8/01 -0800, Mike Wagenbach wrote: > > > Boat wakes come to > >mind. Anyone know if 8 inch/ 20 cm wavelets are significant? > > As you would expect at race pace almost any wave can be significant. > Particularly > if you are "running" perfectly level, and the waves introduce a bounce > (reducing the > hull's glide) into the motion. The waves are significant in that handling the rougher stuff is definitely a different skill than racing on totally flat water. I have been in two races where I pulled away from competitors that I was having a hard time keeping up with in flat water and when we hit the open, choppy water. > I would only do the testing on a lake. I would not do it anywhere with a > current and preferably in water at least 10 feet deep - minimizing the effect of > > the bow wave in relationship to the bottom. I have seemed to settle in on a depth of 3' - 4' to not feel the drag of the reflective wake off the bottom. What are other opinions on what is a depth at which one is not affected by one's own reflective wake? Regards, Ellis Seda Impulse Lat 39o38'40" Lon 75o57'00" *************************************************************************** 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 08:05 AM 3/8/01 -0500, Ellis Andersen wrote: >> I would only do the testing on a lake. I would not do it anywhere with a >> current and preferably in water at least 10 feet deep - minimizing the effect of >> >> the bow wave in relationship to the bottom. > >I have seemed to settle in on a depth of 3' - 4' to not feel the drag of the >reflective >wake off the bottom. What are other opinions on what is a depth at which one >is not affected by one's own reflective wake? I'm pretty sure the effects of the reflected bow wave are at depths less than half the waterline length of the boat. Which is why I suggested 10 feet (3 meters) being a good depth requirement for trials. 3'-4' is very noticable. I find I'm a lot more sensitive to the effects of water depth when I'm in the bow of a tandem racing canoe than on my surf ski or in sea kayaks. In the tandem canoe I'm convinced I notice the effects of water depth at about 8'. Now if John Winters were around he would definitely dispute this "feeling" of a difference at depths that deep. *************************************************************************** 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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