Hull Design ranking

I ran across a thread on hull design rankings for 100 British kayaks. I believe Cooldoctor1 posted it. Now I can’t find it. Could someone post the link?


– Last Updated: Jan-09-07 4:27 PM EST –

But it doesn't rank design - just drag under limited/controlled circumstance. Limited use beyond splitting one hair in the beasts knotty mane.

It looks…
like there are a lot of fine boats missing from this “survey”

It’s a few years old (nm)

That is it. Tnx, Greyak

– Last Updated: Jan-09-07 8:51 PM EST –

It's a bit surprising to see a folding kayak ranked #12 - higher than expected.
It's also interesting to see that the two S&G boats (Pygmy and CLC) are far apart.

I only saw the Pygmys
the problem with this scale is that it’s based on calculations for a particular speed range. I wonder what would happen in a tank test.

Notice the plastic 'Cuda at #20! Yeah!

is under Superior Kayaks - #1!

A clarification…

– Last Updated: Jan-09-07 11:52 PM EST –

The Superior Kayaks "Hawk" (19'2" LOA, 21" beam) is not the same as the WS/CLC/Superior Kayaks "Arctic Hawk" (18' LOA, 22" beam).

On that list, it's the Superior Kayaks "Hawk" listed as No. 1, and the WS (composite) Arctic Hawk is ranked at No. 5 in the 4-5 knot rank.

I have one of the CLC Arctic Hawks (same dimensions as the WS composite AH), and I can attest to its fine speed, glide, etc. Still though it's not the "Hawk".

If you look at the Superior Kayaks site (page 19), you'll see all the various "Hawk" versions:


I notice the absences more.
Folks should read the info that goes with that table too to keep the numbers in perspective. It’s more a toy than a tool. Fun but of limited use.

You are correct

– Last Updated: Jan-09-07 11:47 PM EST –

Only the Arctic Hawk is being sold as kit through CLC, not the same as Hawk.

Given that Arctic Hawk design is from Superior Kayaks, I expect that it is closer to Hawk than not.

Can’t judge by maker or appearance…
… like that and have it mean anything regarding performance. You can compare build quality and features/outfitting, but not much else without risking some erroneous assumptions.

Of the Hawks I’ve padded shortest/smallest - Sparrow Hawk, and longest/fastest - the Hawk SS. Different kayaks, in many ways. The Hawk family make all bear a similar family look, but they are all different. Otherwise Mark wouldn’t have bothered to create them all - WS wouldn’t have produced two of them, and CLC wouldn’t be looking at doing two more kits (adding Sparrow Hawk and Hawk GT).

Same for all makers. That’s why they produce a line.

I’ve paddled QCC 500/600/700 - all with a similar look, all handle quite differently. NDK Explorer and Romany - same thing. Valley Nordkapp and Pintail - also have a family look, but are very different on the water, etc., etc.

and what happens on the water are two very different things. If four panel hulls were the prefered shape for things moving in the water you’d see fish, sailboats and surf-skis configured that way.

I wrote the text and still I can only agree with Greyak.

I’ve been criticized by local dealers for even presenting the numbers. As one guy put it: People arrive at my shop with a printed copy of your list. They insist on buying the kayak with marginally the best “numbers” even though another kayak may be much better suited for them.

I haven’t updated the list for a couple of years now and have no plans to unless some revolutionary new design arrives. It’s really all just the same.

I’m a sucker for the concept of fast kayaks to the point where all my regular kayaking is done in ICF racing kayaks these days. But when it comes to sea kayaks - I’m not so sure anymore. I think there’s an unnecessary large gap between so called fast sea kayaks and actually fast kayaks.


Sorry if this has been covered but am I correct that the drag numbers are calculated and not measured in a tank?

…that is correct. The method was described in an old issue of Seakayaker Magazine and compared to actual tank tests.


In other words,
calculated numbers and tank tests are in agreement? So, those numbers do mean something.

But what do they mean?
The calculated numbers no doubt mean something and they may well approximate tank test numbers closely, but the real question is what do these numbers tell us about kayaks being used in routine coastal conditions? Its a little like the stability curves. You see reviews in Seakayaker which talk about a boat’s great secondary stability and how well it performs in rough water, but the stability curve is nearly flat. Then the same is said of a boat with a more “normal” stability curve. Obviously something else goes into the equation to reach those conclusions than the numbers.

one more question
my rough understanding is that the number is a product of wetted area, waterline length and prismatic coefficient in some formula. What I wonder is if that accomodates the actual shape of the hull beyond those dimensions. If you look at the blunt skeg stern on the Mariner Express it’s obviously not a slick form like a Gulfstream. Where the numbers vary by matter of a few percent I would think that shapes would matter.

"the concept of fast kayaks"
Yeah, I’m a bit of a sucker for that too. Who else out there has a 6m x 48cm swedeform SOF, with cross sections more round than square (at least as much as can be done with 6 panels)? L

The problem isn’t the numbers, it’s what people think they mean, and the boats they try to evaluate with such a limited/specialized approximation tool.

I used to spend hours playing with the numbers. Even came up with my own quick wag formula as a comparison tool. Nearly as many kayaks on my list as on yours (and also about as out of date) - many taken off the Broze spreadsheet. I can plug any kayak in if I can get LWL/BWL. I compared my numbers to actual drag calcs plus race and long paddle results while tweaking it so it gets pretty close using only LWL/BWL (leaves out a ton of stuff - but the standard displacements in the drag numbers do to - and there is some general similarity/commonality in form among kayaks to average out some of the rest).

Fun to play with, but my numbers are useless beyond comparing/estimating very basic things - like what sort of gain I might expect (at same power - there is some ability to estimate and adapt this input) going from one kayak to another. A rough estimate of casual pace, quick touring pace, and race pace. It was useful on a broad scale at a beginner level to help narrow down kayak choices, but I can get that close by eye and basic specs now.

I’m looking at a more specific range of kayaks now, fast sea kayaks and above mostly - where the differences narrow and the numbers are really only predictive for the good paddlers. Plug two top racing skis or K1s into the drag spreadsheets and there will be differences - but quite small and only exploitable by the elite paddlers. Paddler differences still having many choosing on other criteria. Put the same boats into my spreadsheet and they’ll likely be almost identical. It’s just a wag - as intended.

In some ways a wag may even be better that full drag calcs - as it prevents putting too much faith in the numbers when the seat of the pants differences deserve more attention.