Hi Folks,

Just experimenting with channels and I have a design which I dont know will work or not. i have a “child-like” pic I just attached to explain what I mean, could you take a look and tell me if im on the right track of where to put the channels.

Do these channels make a difference to turning?

Going straight the theory seems fine, but do channels hinder or help turning???

On any other board I made, I wanted the tail to be straight and have Sharp rails, this is different, the rails will now have a couple of bumps in them?

Any info appreciated


i’m pretty new at this (ten boards, and no channels yet) but have been doing some reading in the archives on this sort of thing.

now i would say (bearing in mind the vast majority of people on this site have a billion times more knowledge than me) that the first effect of channels is to create a better flow of water around the fin/s, ie, more water to the base of the fin, less turbulence around it etc. this greater water flow and lack of turbulence means that the fins effect on the water and vice versa (and consequently everything else to do with surfing) is more pronounced.

the second is to (and this is the one i struggle with, but as i’m the only one to respond at the moment, i’ll give it a shot) reduce drag, this happens because (literally 34% sure about this, ie not very) they create a small cushion of air due to the increased area under the board the water has to fill. i think that this paragraph might well be the crappest explanation of anything ever on sways.

the third is to act as a small and rudimentary fin, it controls water flow into one direction just like a fin. do a resources search for finless boards.

so overall i think your channels to have any effect on the fins, not long enough to really control water flow and i’d rather not say anything about drag ( i do have a suspiscion that any increase in surface area creates more drag)

search the archives, search for venturi effect/bottoms some of the debate going on in those threads blows my mind, and i must have read them half a dozen times.

remember that i know very little compared to most guys here, and secondly, do it, it might have a placebo effect and improve your surfing (an improvement’s an improvement)

pleas evereyone tell me where i’m wrong,


south wales (old)

That’s not channel.

It’s a concave, like an E-wing, done since 1970. Affects a little.


is what i was saying about channels about right? i was under the impression that he meant them to be like two short channels in between outer arse cracks on the tail. E-wing you say, would a fangtail have more points?

any feedback appreciated,


Hi Sham - What you’ve drawn looks more like “wings/flutes (almost if they had mini channels).” I’ve had boards w/ that feature, and it felt to me like it helped with the turning a bit - adds a bite point, and “softens” up the water flow off the side of the tail. Probably don’t see 'em that much 'cuz, not unlike the 6 channel bottom, there are a production pain.

Pander - you may want to look into “high/low pressure” and/or hydrodynamics in the archives. Channels create high pressure between the board/water = lift/speed. The direction and increase in flow due to the venturi effect is a little more complicated, but it to can be shaped into a board. I would refer to some of the fin discussions w/“Hylceon (sp?)” (I think) Some good info on turbulent flow @ the bottom of board and base of fin… speaks to the “cut away” base.

Good luck - keep up the good work. Taylor