My Enlightenment about Speed

-- Last Updated: Sep-30-05 11:38 AM EST --

I went on a 40 mile trip with paddlers better than I and I am a better paddler for it. Many of my forward stroke ineffeciencies are starting to disappear; there is nothing like pain and fatigue for motivation.

I paddled my Sirocco and, by the end, I was able to cruise with them at around 4.5 to 5.0 mph, something I thought impossible at the start of the trip.

I took that information to the hydrostatics chart compiled by Peter Unold:

My cruising speed places me at overcoming about 1.75kg of resistance when I translate the 4 knot (4.6 mph) hydrostatics for the Gulfstream and add a little resistance for the polyethelene Sirocco.

If you take my new found "cruise resistance against paddling (C.R.A.P.)" of 1.75 kg and translate that down the chart to other boats, that puts me around 4 knots in almost everything listed with a few outliers one way or another. The Perception Eclipse would likely cruise for me just over 3.5 knots while the Arctic Hawk wouldn't be much over 4 knots.

Even a C.R.A.P. of around 3.5 - 4.0 doesn't seem to make a huge difference. That would put me just over 5 knots in the Gulfstream and around 5.5 in the Arctic Hawk. I don't see myself regularly doubling my output.

My bottom line is that there is not a whole lot of difference in boat speed for my cruising effort. My speed will be essentially the same in the majority of the kayaks listed in that chart. I need to favor other factors when I move up to a glass boat.

Apples to apples
If you look at that chart again and scan the entire columns for resistance at all speeds under 4.5 knots you’ll see it makes little difference. The variation is very small and involves mild to easy effort anyway. At 4.5 some variation starts to show and the real pigs and race horses start to stand out. Over that the differences get much more noticeable.

So, while it may not be critical to have the fastest hull for general cruising, greater available sprint speed (at same effort) can be nice to have for safety reasons and comes at little if any cost in efficiency at lower speeds. Other factors are more important (fit, feel, suitability to conditions expected, etc.) but all else equal (never is) I’d always take some free speed. Even 1/2 knot makes a difference when crossing a busy channel.

you got it
and that’s why the Scirocco and Gulfstreams are nice hulls,they don’t take much effort to cruise along for the stability and easy wave handling. The same idea is behind QCC kayaks and Epic kayaks. Reduce wetted area and you got an easy kayak to paddle at cruising speeds,and going fast depends on the motor first and the hull second.

Overlap, lack thereof
That’s what I think is most interesting about that chart. For all the hardshell touring kayaks, there is no overlap between any of the columns. This indicates the difference in hulls to be worth less than .5 knots, for most people, up to speeds of 5 knots and probably more. More like just a tenth or two.

If you can believe what’s in the chart, anyway.

Hull drag is something like a 3rd-power function, even without any waterline-length hullspeed considerations.


Yes, but the chart is for calm water
Once you experience speed comparisons amongst dissimilar hulls in real world conditions that include windage and the “plunging” caused by waves, currents, etc. … then you understand that the overall shapes matter more than is suggested by drag computations/data … and so, are more significant than a tenth or two in mph or a couple % points of resistance. The whole dynamic might best be measured by heart rate (i.e. effort expended) to propel and control a boat in varying conditions.

Now … if someone would just bring me all the boats, instruments, etc. and pay me to test them for a few years … that would be good. And even if that doesn’t happen (hehe), I’d like to see more people post their speed and heart rate data like Marek does with his boats. It’s vary interesting to compare real world performance between such dissimilar boats.

I fear those numbers can’t be completely counted on, because of what you just said and so much anecdotal evidence that seems to suggest greater differences. But, they seem to be all we have that isn’t subject to far too many variables.


Drag = effort expended
as far as the hull goes. Effort spent staying upright and on course adds to that real world as you say, but also has more to do with skill than hull and becomes a huge set of variables that are useless for comparison.

Say what?
Just because something is hard to reduce to a number doesn’t make it useless for comparison. It just makes the comparisons harder to do.

Challenge! Is There An Optimum Speed?
Drag increases dramaticly as speed increases.

“Efficiency” is covering the most distance with the least effort.

Therefore the slower you go, the more efficient?

Is there an optimum speed to cover the most distance with the least effort?

Or is the answer “as slowly as possible?”


There’s going to be some stickyness at the low end. You have to have enough force to overcome the adhesion of the water to the hull.

significance of a few tenths of a knot
On the significance of a few tenths of a knot:

4.0 knots x 2 hours = 9.2 statute miles

4.2 knots x 2 hours = 9.7 statute miles

4.5 knots x 2 hours = 10.4 statute miles

Whether covering another 1/2 to 1 mile more in the same time is useful or not I leave to the reader. It’s obvious to the racer, but has other applications like getting to the takout faster in deteriorating weather.

Looking at it another way:

10 miles at 4.0 knots takes 2:10:30

10 miles at 4.2 knots takes 2:04:15

10 miles at 4.5 knots takes 1:56:0

14 minutes less could mean 14 minutes out of a T-Storm, 14 minutes closer to a Hospital, or simply 14 minutes of bragging rights.

If you like slow, go with slow - just don’t expect a tow!

Feel free to try…
…but most of the variables cannot be objectively measured to begin with. Drag can be. Even stability curves make a lot of assumptions and don’t match with individual paddlers experiences. Both are only really useful for comparison if you understand how to interpolate the numbers to your size, skill and paddling. A wag.

Nothing wrong with using subjective feel for evaluating to meet personal needs (beets other’s numbers any day!) - and maybe for same person to compare many hulls, but not for people to compare with each other on things like “rough water” handling. No one can even agree on what that means! Quantify it? Good luck!

Not trying to be argumentative - just pointing out obvious limits to usefulness of numbers.

There is an optimum speed…
… but it is different for every combination of hull, paddler, and conditions.

You still seem to be saying
that we should rely primarily on a number that’s admittedly of limited value because we can’t come up with any other numbers. My point is that relying on numbers is a bad idea, period, unless you’re planning to spend all your paddling time on flat water with no wind. If you plan on encountering either, you need to get out and PADDLE the boats you’re interested in, gather information from others who have paddled them in a range of conditions, etc.

paddler VO2, etc.

No, I’m saying to rely on…

– Last Updated: Sep-30-05 9:51 PM EST –

... your butt in the boat primarily!

Don't get too hung up on that "flat water only" stuff either. Hulls make a difference but that usually has a lot more to do with the paddler. A lot of boat people see to think are flat water hulls aren't (like my 700, the EPIC 18...).

I would imagine . . .

– Last Updated: Oct-02-05 1:40 PM EST –

that the optimum speed would be on the flat part of the water resistance vs. speed curve just before it gets steep.

I was trying to find an "optimum boat" for my comfortable cruising output and I was somewhat surprised that there really isn't much difference in boats at my cruising effort.

Greyak does point out that at the top end there is a difference and that 0.5 knots can add up at the end of a paddle. Yet, to experience a 0.5 knot difference, I would have to double my paddling output which would not be feasible for me right now for anything more than a sprint. As my cruising paddle output optimizes with refinements in my stroke, I will get to the steeper portions of the curves for the slower boats and more differences will come into play.

I do note that some boats give you speed at sacrifice of other good qualities which is a price I am now less willing to pay after my "enlightenment."

I have figured out that much.

But this enlightment has further implications as far as boat design.

Shorter boats handle better in the surf. If you value that the challenge is to figure out how short you can go and still maintain a crusing speed that will alow you to keep up with a group of more traditional sea kayakers. I think the answer is probably shorter than most people suspect.