Water resistance/ speed

Someone posted a link to a table of water resistance for 100 boats some time back. While in persuit of a new boat I looked it over to check the numbers for the boats I am interested in purchasing. It lead to some confusion (as if selecting a new boat isn’t confusing enough). The sonoma 13.5 has less resistance than the Cape Horn 17 and the Eclipse 17 until about 4 knots (which makes sense, sort of). It was suggested that average boat speed is 3 knots. If this is true, then the larger boats, which only add a small amount of extra storage, are not a good purchase. I’m sure someone has tracked their speed with a GPS on a touring boat, is 3 knots acurate?

3 knots is a good average.


water resistance/speed
Where is this table of water resistance, please?

3 knots and resistance
If you are thinking of touring boats (kayak 15+ feet long, 24" or less wide)there is very little difference in drag at average speed (3 knots, though some say 3 mph - which is a bit slower). It is at 4.5 knots and above that the diffeence in resitance is notable.

Unless you are racing, there are many more important factors than resistance.

It would be worthwhile to check out Sea Kayaker Magazine reviews for detailed information on an array of aspects significant to kayak performance.


but read about how it was measured - all kayaks with the same weight…

All depends on the motor !
Longer, skinnier, and lighter is faster with the same motor paddling.



No - not always. At low speeds longer isn’t better.

The wetted surface is greater and gives more resistance.

water resistance
i se that this table of water resistance is for kayaks, is there one for canoes?

He said “faster”, not “better” NM

3 Knots
Whenever you read that you have to have some idea how it was measured. I average somewhere around there for a 3-4 hour outing but that’s because I paddle at 4-4.5 knots for stretches and then bob around resting and looking at wildlife and river traffic in between.

Depends on where you are paddling, on the Hudson here I’m interested in covering some distance each time I go out. Would not be happy with such a short boat.


The same
OK, it’s not better AND not faster. :wink:

Good point
"Average touring pace" may not be the same as “typical paddling speed”.

And as another post said, it’s important to match the boat to the paddler and the intended use, not just look at numbers. My small, non-athletic wife is faster and happier in a small boat that fits her than she was in her previous longer boat. A strong fitness paddler would move in the opposite direction.

Silly argument
There IS a difference in terms and is does matter.

What’s silly is the limited relevance of this tired old argument about short boats being faster at slower speeds. Faster at slower speeds? Makes no sense. More efficient maybe, but who cares about resistance at around 3 knots or less where most kayaks intersect or are very close on the drag curves. The differences are too small to matter. Few would even be able to feel it. Your talking ounces of force in most cases. At 4 knots and up your talking pounds. That matters and longer boats rule.

Not just water resistance
How about wind and waves? There comes a point when extra leverage out at the ends becomes a real issue, especially with the wind forward of the beam.

I’m hearing this from a 21’ ski paddler?
Tell me it ain’t so! L

This ain’t a best/better/ultimate boat thing. Not talking about anything universal. They all have pros and cons. Trade-offs. Balance. More about design intent/intended use really.

If you want to go really slow and are weak/feeble, or are fit and want to aggressively play sit 'n spin in a washing machine - I certainly won’t say go long.

In 2-3 foot wind wave chop I’ll late my 700 over our Pintail any day though. A lot more fun ride. I like to actually paddle in open water, not cork around. In surf, probably the other way around. Someday I’ll get to try a surf kayak and a WW boat. It’s all good.

Ski is a LOT of work in big stuff
Example: my Monday spanking. I knew the wind had come up, wasn’t paying as much attention as I should have to how much it had come up. I’m out of shape and just starting to work semi-hard at getting back into shape, which meant I had exercised pretty hard both Sat. and Sunday (running and then surfing) and didn’t have a lot left on Monday. So I get out on my downwind run, and about when I get to the most exposed part of it, I’m starting to run out of gas. By the time all was said and done, I’d had three swims, one of which took probably 10-12 re-entry attempts before I got up again, and a paddle that should have been around an hour and fifteen minutes took a little over two hours. Why? Because if you’re not moving the ski well, it’s twisting and hobbyhorsing and pointing the bow at the sky and all kinds of stuff that isn’t getting you closer to where you’re going, and every time it gets stopped on the back of a wave you have to accelerate it again. And that’s downwind. Upwind is actually HARD!

Contrast at the extreme other end of the scale: a couple of months ago on a similar day, I paddled my little Wave Witch out to the Diamond Head buoy just for the hell of it. Now, there’s no way a 9’ boat is ever going to qualify as fast, but it was totally unaffected by the wind and moved about the same as it would on flat water. It was kind of fun to be sitting there amid those big piles of water with the wind blasting on me and not be fighting the boat.

If I’m going to be out in big stuff for an hour or two, yes, I want the ski. But as the pace starts to come down from pushing hard to something that’s sustainable for several hours, I have no trouble at all believing that I’d be faster in a shorter boat than a longer one for the same level of effort, and the level of effort I’d be putting out is still quite a bit higher than the average pond paddler.

You have to go really small to see
To see a big difference in speed for touring boats you have to go really small. My blackwater 11.5 is really fast compared to white water kayaks with a top speed of 5.1 MPH and a cruising speed of 2.8 MPH. It’s much longer and much faster than the other boats and I’m strong enough to paddle it at its top speed.

Copare it to a 16 foot touring kayak with a top speed of 6 MPH and you can see a big difference. Once the boats get longer than that I just can’t sustain the effort to keep the boats going any faster than 6. And in all 3 to 4.5 MPH is my reasonable paddling speed for any period of time over an hour.

to all for the input

Another thing to think about
Nothing scientific here, but I have the sense that if you added a 50 lbs of cargo to a 13 foot boat and 50 lbs. of cargo to a 17 foot boat, the shorter boat would have a greater increase in draft (and wetted surface) and would begin to bog down at speeds of even 3 knots, while the longer boat would be much less affected by added cargo weight.

“Longer, skinnier, and lighter is faster with the same motor paddling.”

If the motor doesn’t have much power, a shorter boat can be driven faster than a longer boat. That’s all I wanted to say. Starting point was the water resistance at different speeds. At low speeds shorter boats need less paddling power, if everything else is constant. I’m not speaking about their maximum hull speed.

The initial question was if it’s true that shorter boats can have lower water resistance in speeds up to 3-4 knots, and if this is a typical cruising speed. The answer is yes. If you want to be faster, you need a longer boat, sure.