Fish form kayaks, symetrical, etc.

I know what the terms mean, but have no real idea of what these design differences accomplish. Anyone care to share their knowledge here? What effect do these design differences make in how a kayak may handle, turn, track, or even affect speed?

A little bedtime reading
An interesting discussion here from some of the big boys in kayak design, i.e. Matt Broze, John Winters, Nick Schade:

Put on the coffee pot…

when I have a free day
and it’s raining outside, I’ll read the link provided.

but it’s a little late in the day for that much caffeine ')

those terms are just shorthand reference to where the widest part of the boat is relative to the cockpit.

as to how they handle, speed, etc. there are so many factors besides that. So many subtle things. Add to that the technique and physical requisites of the paddler and you have an impenetrable matrix.

Wouldn’t let it determine which kayak(s) I buy.

Or which one(s) I like.

maybe this doesn’t answer your question OP, in the way you might have expected - but it helps clear the air of kayak dogma.

big brush
If i may paint with broad brush strokes,

from what i have gathered it goes thusly:

Fishform is stable

Swedeform is fast

Symmetric is whatever the designer wants

Actually, it’s more like…
Fishform is whatever the designer wants

Swedeform is whatever the designer wants

Symmetric is whatever the designer wants

The overall shape of the boat is only one aspect of the design and there are other criteria that strongly influence the handling. As with chine shape, you cannot generalize about the effect, as it’s different on different boats.

Thanks for that link
Personally I like reading comments from people who know more than I do about kayak design - with or without coffee. A rainy day doesn’t have much to do with whether I am outside or in these days…

I think the neatest part is the back and forth and disagreements between them.

I’m confused, care to saplain someone?
If my understanding of John W.'s writing at that link above is correct in that most of the water “flows” under the hull, then the swede vs. fish (as seen from above at the waterline) would not matter as much for resistance as would a swede vs. fish as seen from the side at the waterline. Wouldn’t this be the case?

What I mean is if the water is being pushed mainly under the hull, then a hull that gradually gets deeper in the water (from front to back, as seen from the side) even if it is wide and flat when seen from above, would be more efficient in terms of wave making resistance than a slim looking (from above) swede form hull that has a poorly designed “water entry” area for lack of a better term.

I know there are tons of factors, just curious about that one in particular…

It isn’t actually the width
When talking swedeform, fishform etc., it isn’t necessarily where the maximum width is, but where the area of maximum underwater volume is or rather the point on the hull which will displace the most water as it pushes its way through. Often it’s at the widest point, but not always. It could be at the deepest.

Are you a real Capt?
If so you ought to know the amswer :slight_smile:

There are a huge number of variables other than platform shape, but the slower the water is accelerated away from the centerline the lower the resistance is, the swedeform with the widest part towards the back of the boat allows for a very narrow angle of entry (the angle of the V of the bow shape) so the acceleration is lower and the drag too is lower.

Another factor is a swedeform allows for a paddle placement closer to the center of the hull, more important with a wing stroke.

Bill H.

A real Captain?
More of a has been, I’m afraid. Retired airline pilot, flew corporate for a few years, then hung it up for good. The old 6 pax Coast Guard license has expired, too, so now I just play hard. But somebody has to do it!

great discussion
The take-away message is that “British kayaks have features that make them immune to the laws of physics”.

Good on ya!
Couple of pals fly for Alaska and while they like their jobs it isn’t the career it once was.