What you say makes perfect sense, especially now that you've supplied additional information. However, once again, this is an example of a situation where there's a compelling need to maximize the boat's speed, which is why everyone is working so hard that "hitting the wall" (I think you were referring to the energy output of the paddlers) is a possibility, and that the difference between being fresh and being tired is so obvious in overall performance of the team. Therefore, once again there's most likely a need to recognize a difference between what's "effective" at achieving high speed and what would would be "efficient" in terms of energy usage at a speed more like that of a typical paddler. You could do the same sort of trial at speeds more typical of the average paddler (say, at a speed that is no greater than 2/3 of hull speed), but then each paddler's level of exertion would be so minimal, so far down the scale of their available potential for power output, that I'm quite sure changes in heart rate would be unrecognizable among random error (even thinking about the speeding ticket you got last month will probably raise your heart rate more than paddling 1/4 of a mile per hour faster if you are at a comfortable all-day cruising speed), or at the very least, would probably not be statistically significant if observed (which again would primarily be a function of observed change relative to natural variation). Of course, maybe if you ran these trials for a long enough time to work through the clutter of other interference, you could reach a conclusion. I just think reaching a conclusion with such a trial at such moderate speeds would be incredibly more difficult than when at racing speed.
So, once again, I have no trouble believing that in-synch paddling is "what works best" for maximizing boat speed because the real-world evidence supporting that notion is compelling. However, I've seen nothing mentioned so far that would carry the same weight in regard to in-synch paddling being more energy-efficient at moderate speeds, so I think full instrumentation would be the way to attack this problem.
Hope this lands between GBG and SB Seat 5 in the Va’a can easily be paddling different water than seats one and two and sometimes will even wonder what the heck is going on up there!! LOL Especially so in waves.
Up to seat one feel whats going on and to adjust and sometimes ‘sacrifice’ themselves for the better good of the crew to accomodate the engines in the back who often prefer a longer, deeper stroke … ONE AND TWO , REACH REACH !!! : )
Everyone gotta hit same time … Even paddle offset critical here.
Higher speeds of the double can allow a slightly larger paddle ( upshift ) all other things being equal. But still the paddling pair must tune blades/lengths together to best work symbiotically.
I brought up proper forward stroke technique because I quick realized that recreational/touring paddlers tend to ""move water"" (I know you understand what I mean) as a paddle boat than to move the boat pass a fixed point; thus, under that "improper" scenery, somehow, I could "try" to understand where these guys are coming from...
Anyway, to me this discussion is as bizarre as the one a guy was proposing a "sliding seat" would be more efficient/effective to paddle a kayak. Above all, when one of them seems to have every paddled a k2 or k4...
...my mistake, how in the world, I got tangled with such ridicules discussion :D :D :D :D :D
Imagine you have two buckets, same size. One has a 1" diameter hole on the bottom, the other has a slightly smaller hole in the bottom. Ignore the specific numbers EXCEPT that the second hole is smaller so that water can come out of it at a slightly slower rate compared to the first hole.
Now, imagine there are two people pouring water in (one in each bucket) with two cups each. In the first bucket, you pour with both hands holding one cup each (e.g. you empty two cups simultaneously into your bucket). In the second bucket, your buddy is pouring one cup at a time - left hand first, right hand second. The cups are all the same size. The timing is such that every time you pour your two cups, your buddy pours with his right hand and while you are filling-up your cups he is pouring with his left hand.
Basically, both of you are pouring water at the same average rate. You are doing it 2x slower but 2x more water each time, he is doing it twice as fast but with 1/2 the water each time. The end result, if there were no holes in the buckets, you would both fill-up the buckets at the same rate.
The size of the cups and the speed with which you both pour is such that both buckets will fill-up eventually: the drain holes drain less water than is being poured-in.
You are both pouring-in water as fast as you can but maintain that timing. And remember - you are both pouring in at the same average rate: if you were taking the water off two same size containers, both yours and your buddy's would empty at the same rate.
Which bucket will fill-in faster?
Compare to the paddling scenario. The basic presumption there is that both paddlers paddle as fast as they can and use-up the same amount of energy whether they paddle in-phase or out of phase (both cases are actually "in sync", to be precise).
Scombrid and Carldelo and four or five others have been providing really good, well-described, well-reasoned information about their thoughts on this matter, and thanks to the efforts of these people I am finding the whole topic very informative and thought-provoking. You on the other hand haven't made the slightest effort to understand what some people are saying, and have been too lazy to even to make your own posts intelligible. Scombrid, who's "on your side" even pointed out that your description of proper forward-stroke technique isn't even relevant to the topic at hand, and the fact that you think it is illustrates how little you've been paying attention to what everyone else is talking about, or worse, perhaps your inability. I was going to cut you some slack, so I looked at your profile to see what country you are from and what your native language might be and was surprised to find out that you live here in the U.S. and apparently "speak" English, so my patience came to an end right then. I now assume that you read about as well as you write, as that would explain a lot. There's been more really good information provided by people on both sides of this discussion than you are remotely aware, whether for lack of effort or lack of ability. I wouldn't normally make such a point, but the shear contempt you've shown for statements you aren't even willing to make an effort to read and understand makes you a lot more deserving. I loved what Carldelo said about your remarks being so far off-base as to be "not even wrong", meaning, not even as good as wrong. That was well said. If you don't want people to think you are stupid, try to write like someone who made it beyond the third grade, as that'll help a lot.
If you were to even try to keep up with all that's been said so far and you MIGHT agree that nothing ridiculous has been going on at all. People disagree on things all the time, and in this case it's less about disagreement than about trying to present one's personal sense of "reasoning". Personally, I think this has been one of the better discussions that has popped up here in a while related to paddling. We may never get all the details sorted out, but life is like that sometimes (most times, actually). I think this discussion has been one of the better recent examples showing that we have some really "good people" on this site.
It is ridiculous in some ways It really is trying to re-invent the wheel. We aren’t talking an innovation like changing the hull design or inventing a new hyper-efficient paddle. A simple look at the force needed to overcome the drag at a certain speed and see if that force is even possible by paddling out of sync. People that paddle team boats can tell you exactly what happens when the paddlers are out of sync. The boat starts to decelerate no matter how hard the crew is working.
It would be a neat exercise to test and precisely workout the math and maybe a tweak or two could come of it but I can tell you that when an 18kg k2 carrying 160kg worth of crew is going 18kph if you go out of sync then the force applied by each paddler in turn is insufficient to overcome the huge amount of drag at that speed. The boat slows down. My experience in recreational boats is the same. It take more work to go 4mph in the touring canoe paddling out of sync than it does to the less experienced paddler in the bow and let them paddle at their own pace and match them stroke for stroke.
trying to adapt the analogy to paddling I can’t fit the analogy to paddling. Strokes out of phase don’t add up the way that pouring water in a bucket would. Closest I can come is to assert that the hole in the bucket magically gets bigger relative to the size of your cups when you pour in turn and not together.
If it takes 15lbs of sustained output to go whatever speed the k2 is going and each paddler is putting in 10lbs per stroke, the only way to overcome that 15lbs is to generate 20lbs per stroke by combining the 10lbs effort in a simultaneous stroke. As soon at they are out of stroke, even of they are “perfectly” out of stroke such that one starts power immediately as the other exits, then they are applying that 10lbs of thrust to 15lbs of resistance and the boat slows down.
You use up more energy out of phase because you work just as hard but the boat is going slower so it takes you longer to get there.
No argument here + a question: Your example makes sense for overcoming resistance beyond a single paddler’s ability. Still not self evident how much the 15lb of resistance will slow the boat when there is 0 powre applied though (not asking, just mentioning - too many factors involved).
But, what if they are traveling at the same average speed, such that is easily achievable by a single paddler? Which pair will use-up more energy to maintain that average speed? Say they both travel at a speed requiring 5 lb of resistance and each paddler can deliver 10 (arbitrary numbers)?
Once again, based on the pounds of thrust in your examples, you are clearly talking about extremely high travel speeds (I once used a friend's electric fishing motor that puts out 18 pounds of thrust and it would easily push a small, overloaded fishing boat much faster than it would go with two people at the oars. Of course, that's continuous thrust rather than being delivered in pulses, but the motor made the boat go well over hull speed, something that two rowers couldn't have achieved in that particular boat no matter what. Of course, maybe you just chose those numbers based on an over-estimate of how much thrust the average person generates when paddling at a comfortable pace. Of course, even this is all over-simplification because the maximum thrust that can be generated by oars is less than that which can be generated by paddles, but oars are normally faster than paddles simply because each thrust occurs for a much longer period of time. then again, there are always TWO oars, which perhaps is evidence that everything you've been saying is correct. What fun.). Anyway, that's why I think it would be really cool to see what instrumentation would show regarding the two paddle methods when at moderate speed.
Still, I am pretty sure that whichever paddling method one looks at, there are factors which we are not seeing or understanding. I can certainly see the possibility that what you are saying could be true at moderate speeds just as it is for high speeds. It's just that based on my own experience, I know that it's very easy for the paddling sensation of effort when out-of-synch to be contrary to what's actually happening, as I described in an earlier post, for me to take it at face value. It doesn't mean I don't believe it, only that I'd need something more definite and which clearly "adds up". I do know from personal experience that it's completely wrong to go so far as to say that when two people paddle out-of-synch, only one person's worth of thrust is being used to get the boat up to whatever cruising speed is attained, because out-of-synch or not, the boat will go a lot faster with two people paddling than it will with just one (I'm already losing track of who said exactly what, and I'm not so "in to it" to go back and look). I do appreciate the effort you put into your explanations though, and it's only because of your effort that I can recognize the possibility that the in-synch method might be more efficient at all speeds, not just high speeds.
This is a neat topic to try to understand because of the way that all the variables which affect speed change so drastically with small changes in boat speed. The end result of all those interactions is bound to sway one way or the other based on their relative effect, which MIGHT not be the same at all speeds, and if "what makes sense to me" turns out to not be "the way it really is", it'll be because some changing variable counteracts another to a greater degree than I expected (it seems like the most likely possibility in support of your view, if it's true at all speeds, is that the boat's momentum more than compensates for the greater increase in drag resulting from a greater burst of acceleration with each (in-synch) stroke. This is a more complex paddling problem than any I've tried to figure out before, and it's been kinda fun.
A paddle boarders are another example - they could paddle with both hands as in a butterfly swim or can paddle feft-right as in crawl swim style.
Again, there are probably other factors. Boarders seem to alternate which style they use.
Swimmers, on the other hand, universally use crawl as the fastest instead of butterfly and they do have a choice…
Someone with time on their hands so to speak, can probably try it in their kayak - paddle it without a paddle crawl vs. butterfly style and watch the hearrate monitor -
yeah, I was sloppy in terms Yes, we generate thrust by imparting momentum on the water mass that we are in. We are trying to do it while leaving the smallest possible skid marks considering that we are operating in a fluid.
iceman if two people are paddling a tandem with cockpits far enough apart to not clash is there any difference between in synch paddling on one side and in synch paddling on opposite sides? My point about on side in synch paddling coming as a consequence of boat design and close cockpits is a valid point as the boats would be ridiculously long with four paddlers with cockpits far apart and it would appear to me that in a tandem having two paddlers far apart makes for a less sea worthy design having large masses near the ends in waves.
Guidelines for the discussion I see many of the posts are during weekend daylight hours. Why are you in front of the computer when you should be outside paddling?
I’d like to clarify my question. Many people here are posting responses based on typical K-2 races. The kayak my brother-in-law and I are paddling is an 18’6” x 27-5/8” CLC Shearwater Double. This is a slow boat but very comfortable and stable in Force 5 winds. We recently competed in a 50 mile race with the WaterTribe in NC two weekends ago. We plan to compete in a 100 mile race next year and possible a 300 miler in the future. The kayak we are paddling is well suited for distance races and rough water. It’s efficient at slower speeds but is a barge at higher speeds. Still, we managed to finish the 50 mile race in 10 hours against a 10 knot headwind and fighting currents.
Our paddling strokes per minute are governed by our heart rates. We paddle at the top of zone 2. For me that’s around 135 bpm. At that heart rate, we can replace spent carbs as fast as our bodies are burning them. We would bonk at heart rates any higher than that. Our bodies are burning primarily fat. During the race, I burnt 1022 grams of fat as calculated by my heart rate monitor. Since we need our bodies to endure 50 miles, food or “fuel” management is a huge factor and our calories are calculated based on the distance and duration paddled.
Considering I paddle 3 strokes for every 2 of his, I’m not too optimistic that paddling in sync will provide positive results for us unless we also change our paddles. I need more surface area; he needs a shorter length shaft. We can certainly change our paddles to slow my cadence down and speed up my brother-in law’s cadence. He and I have decided we will try paddling both in sync and out of sync and measure the results of our average speed and calories burnt each way (assuming we will have consistent conditions to paddle in).
So, the discussion on the benefits of paddling in sync while racing K-2’s is appreciated and very interesting but our paddling is based on much slower speed and longer distances. We are not trying to max out the speed of the kayak over a short distance. Perhaps some day we will. I’ve been eying up the WSBS Bullet K-2, but can I really stay seated comfortably in that for 100-300 miles?
Do you remember the story of the tortoise and the hare?
Busted Well, I’ve been reading and replying to this thread in between grading papers, preparing lectures and going to endless meetings. It’s not paddling, granted, but that’s not an option this month. At least this keeps me thinking about kayaks.
Very interesting the conditions you describe. In my imagination, you are working right on the borderline where it isn’t clear which is the best paddling scheme. If you do take any data, I’m sure we’d all like to hear about it. I am certainly planning on designing some experiments to address the issue, but that’s pretty far away - probably not until next summer.
I paddled sat and sunday I logged 60km this weekend in addition to a 10km run and fishing for 3 hours yesterday to catch a mess of bluegill for tonight’s supper. First cool whether in several months and I dumped all responsibility to goof off. I’ll admit to posting during a feeding between paddling.
