Why is it that it seems the less effort I put into paddling, it is easier to paddle!?
When I decide to take it easy and go slower I seem to glide effortlessly with my kayak. When I’m putting gusto into it it seems it’s a lot of work and I’m not really going that much faster? (although I’m not sure if I am going slower, or it’s the same, or even faster when I’m paddling slow and steady.)
What is happening?
I’m a beginner kayaker, gone kayaking about 12x, including 2 classes with L.L.Bean.
Your perception is good
– Last Updated: Aug-17-13 5:40 AM EST –
Every boat has a top speed, defined by it's hull shape, dimensions, rigidity and finish. When you approach this top speed, any extra effort is wasted. If you want to go faster than your current boat allows, then, you'll need a longer, skinnier boat (and more rigidity and slickness can help). This is one of the big differences between "recreational" kayaks, and "touring" kayaks, or "sea kayaks".
In seeking a faster boat for YOU, remember that, for each person -- considered the "engine" -- there is also a limit to how much boat you can efficiently push, and it is counter-productive to paddle a boat that is too long. A larger, athletic person can get more out of a 17-foot sea kayak than a smaller, and/or less fit person can.
A 14-footer is a good length for most people to try, and, you can decide if that's a step in the right direction, and, if you may get more out of 15, 16, 17 footers.
Edit: I should also note that shorter boats are more efficient AT GOING SLOW. If you want to relax, and NOT push the limits of your boat, then, you actually work less by paddling a shorter boat. This is one reason many of us end up with several kayaks. I'm taking my 14-footer out today, because I will not need the speed of my 17-footer.
GPS
– Last Updated: Aug-17-13 8:27 AM EST –
Set a GPS up in front of you and paddle easy, hard, then really hard. You'll get a very good idea about how these boats work.
(Return on your investment).
Fluid dynamics
Drag increases as the speed squared. Power required increases as the speed cubed.
yes, exactly
You are probably going to get all kinds of responses from engineer types talking about fluid dynamics, theoretical hull speed, bow waves and all kinds of good stuff. But basically what you just asked was, “Why is it when I paddle harder it feels harder and when I paddle easier it feels easier?”
You can figure that one out right?
I’m just messing with you. The engineering stuff is actually really interesting. Welcome to the kayak world!
You may have recently learned
some technique. It takes time to paddler at a higher cadence and maintain good technique, as your muscles are not yet independent of your brain.
What do you mean by working harder? If you are lengthening your stroke you are self defeating your purpose.
That’s it in a nutshell…
…plus the advice about shorter boats being easier to paddle at low-moderate speeds.
finding the sweat spot
Every time I start or restart a new sport I go from poor to good fairly quick before leveling off. I find the biggest part of this from an effort perspective is finding a pace that takes effort but doesn’t push me past a point where I exhaust fast. So at first I tend to burn out too quick. But it’s not just the overall power you put in. It’s finding the right cadence too. In the long run a faster cadence is often best in many sports like paddling and cycling but your body need to slowly ramp up to that or you tire and your form falls apart. So to get better you discover a comfortable pace and cadence that you can go a long way with. Then now and then try pushing both up slowly for a bit before going back to that nice cruise pace.
This may be it, it was a short boat
It was a short boat… only 10 feet. This may be why… didn’t realize it could only go so fast lol.
It may also be with the cadence as well. I think I may be tensing up when I try to exert too much and it appears the boat really isn’t going that much faster than when I didn’t try so hard… so it was more enjoyable.
I was betting…
that you’d respond and say you were in a short boat! Next time you go paddling, see if you can try a longer (around 14’) boat and try the same experiment. I think you’ll get some different results. If you want to go further, repeat with a 16’ boat.
The shop that I used to work at used 14’ boats for tours, because anything shorter and we couldn’t get a group of (usually) novice paddlers anywhere in 3 hours. In the longer boats we could actually get around and see some scenery without wearing people out. As a guide I had to pick and choose what boats I paddled, as some were too fast - no matter how slowly I tried to paddle, I was still schooling the rest of the group.
Pretty good observation
– Last Updated: Aug-21-13 9:43 AM EST –
I see a lot of rec kayakers, mostly young men, who are constantly trying to power themselves along at speeds which are not efficient for the length of boat. Several of the earlier posts sum up the situation pretty well, but it seems a lot of people do not easily become aware of what you have noticed pretty quickly.
Your ten-foot boat has a theoretical maximum speed that's probably pretty close to 4.7 mph (assuming that about 6 inches of the overall length is above the waterline. Note, the boat CAN go faster, but it takes Herculean strength to make it happen. Also, the amount of effort it takes to go around 4.0 to 4.3 mph is probably too great to maintain for long periods of time. By contrast, the maximum speed of a 14-foot boat, again with six inches being above the waterline (making it a 13.5-footer) is about 5.6 mph. The difference between the two boats at cruising speed will be similar. That doesn't seem like a lot in terms of actual speed difference until you think of it in terms of percent difference, or compare distance traveled over time for the two boats. In rough terms, for every five miles someone goes in their 14-footer, you've fallen behind by a mile in your ten-footer. There's nothing wrong with short boats. They just aren't the right tool for the job in certain situations. They can be the right tool for the job in others, though I dare say ten feet is shorter than what's ideal for most "short boat" situations.
Speed rule of thumb
top speed of a typical kayak is 1.5 the square root of the water line in MPH
25 foot water line = 7.5 mph top speed
16 foot water line = 6 mph top speed
9 foot water line = 4.5 mph top speed
in addition to this very rough rule of thumb you need to consider your ability to power the boat up to its top speed. For example I can power a few 16 foot boats to 6 mph but I cannot power a 25 foot boat to 7.5 because I just run out of steam to push the big boat faster through the water. On the 16 footers I don’t run out of steam but the boat hits a wall where more paddling makes a bigger wake but affects the speed very little.
what about width?
BTW,thanks for that rule of thumb.
would the 1.5 factor change to compensate for boat widths?
Width doesn’t affect top speed, …
– Last Updated: Aug-21-13 7:42 PM EST –
... but it does affect the needed amount of effort, much as hull cross section affects effort. Theoretical top speed is based on the idea that a displacement boat cannot go faster than the waves it creates. At top speed, the boat is traveling between its bow wave and stern wave. The longer the boat, the longer the wavelength, and the longer the wavelength, the faster the waves travel. The faster the waves travel, the faster the boat can go without needing to climb out of the trough between them (climbing out of that trough is what a paddler normally doesn't have enough power to accomplish).
By the way, I wouldn't be surprised if the idea of "climbing out of the trough" isn't the most accurate way to describe the situation, and engineer types like Carldelo understand this way better than I do. However, that wording is pretty accurate in terms of what the problem looks like in actual practice.
The sweat spot
is where I start off in any exercise. The sweet spot is another thing entirely :).
But yes, there is a point of effort/progress that is optimal for a paddler. Once found, it can be maintained for hours without need for a signficant amount of rest. Unfortunately, even if you balance everything out so that you can maintain cadence for long periods, the prevailing conditions can jump in and change things considerably. On flat water, with mild winds, it is pretty easy to find. In rough conditions, following sea, rebound waves, etc. it’s another story entirely.
Rick
rules of thumb
a 16" x 17’ boat can do about 10.5 mph over a 1 km course.
a 17" x 21’ boat can do about 9 mph over the same distance.
Width matters in kayaks where power is limited and balance comes into play. The sweet spot for speed is about 16.5" x 19’ long.
proportional
That’s an important point – a “faster” boat still needs an appropriate “motor” to drive it to it’s full potential.
An all-too-common mistake is to put a smaller/weaker paddler in a longer boat and assume that they’ll be faster on the water. Sure, going from a 10’ boat to a 14’ boat will probably help, but going from a 14’ boat to an 18’ boat may just be frustrating. You want a boat that will be efficient for the paddler at the speed they want to paddle. What works for a world-class athlete may be a poor choice for a recreational paddler.
The total drag force is a combination of form drag and skin friction. Skin friction dominates at low speeds, so if someone’s not interested in speed a smaller hull with less surface area can be more efficient.
A narrower beam, with less cross-sectional area, will usually be more efficient than a wider one. A narrower boat also allows the paddle to be closer to the centerline, which is more efficient.
A hull with a semicircular cross-section has the least surface area(skin friction) for a given volume, but is unstable. Trading off stability and drag is one of the many compromises of hull design.
For ww paddlers, a 10 foot ww kayak
feels terrifically fast, compared to the seven and eight foot “new school” boats that are on the market.
But take a 10 foot ww kayak out in the middle of a big lake, and try making good cruising speed, and it will seem glacial.
One just has to find out the maximum speed a kayak is willing to go, before it’s climbing its bow wave. Then learn to paddle efficiently to get the best speed return out of the hull, consistent with acceptable effort.
Ever Watch an Elite Paddler?
See how they make paddling fast look so easy and effortless? Well, you’ve discovered it, so now work on it with the goal of increasing your distance per stroke with the least amount of effort. As the coach will always say: “you got to learn how to paddle slow before you can paddle fast.” Good luck.
Surfskis or custom race boats?
Are any commercial kayaks 16" wide, I don’t think I’ve ever seen such a beast. I’ve tried a few surfskis and 18" wide was fairly challenging to paddle, 16" must be interesting.