I always wonder how the Tail of Tomo concepts with channel tails work compared to a V-Bottom.
A V-Bottom has the flattest rocker in the centerline and due to the V more rocker at the rails.
So when surfed flat i get speed from the center and when put on the rails it turns on the rail rocker.
But what does a channel tail?
Surfed flat it get's the speed from flatter rail rocker, put put on rails it stays on the flat rail rocker, so stiffer?
But when/how works the deeper centerline rocker? in tight cutbacks with a burried tail?
Does a channel bottom have more, less or equal rocker like a v-bottom?
Why has a Fanatic Stubby or Naish Raptor a V-Bottom and a JP Wave Slate or Hypernut a channel bottom?
Anyone out there to explain? Shape-experts?
Advantages/disadvantages?
Just curious,
Alex
To give a response need to be back at some principle.
The actual principle is to transform any water reaction( glide) on the bottom shape into a drive effect and therefore speed, it must be a trim effect as a vertical plan like fins are settled on most surfboards.
In the case of channel the longitudinal concave and ridge are completing the trim effect acting like a small longitudinal fin or extending the effect of base of the closest fin around ( single rear one of the trifin or rear twin ones of the quad)
Last thing to say is to get a glide effect and speed need to apply pressure from your weight or body inertia on the actual concerned surface which is the tail, so in case of the tail channel, this channel at the rear of the board has been located here in response at surfer's bodyweight stance is applied on the far back of the board.
So the rear channel is useful anytime your back foot is applying maximum pressure on tail bottom of board like strong bottom turn or underlip cover.
In one word: rear channel is just made to go for it 
Hi Kami,
i understand that the channel is delivering more grip. But is this the only advantage of a channel bottom?
Or are there other effects on glide, speed and drive compared to a V-Bottom?
For example, what would happen if a Hypernut had a V-Bottom Tail, would it also work?
Alex
Hello Alex, I dont think that grip is the proper term to be the effect of the channel. As my own experience on 6' with 6 channels bottom, the main effect is faster you go more stiffer and therefore fast to faster it comes out. So on tail of the Tomo style SUP, central channel is just a bonus thrust added to the multi fins system ( 3 or 4 fins)
Applied to the Hypernut the central channel is making the V-bottom more positive and reactive without losing rail to rail transition.
I believe in this board, I hope I can get one with a foil
But let the boss talk about it:
Hi Kami,
that's a really good video, thanx.
Do you channel tails on your boards, too?
How do you design the rocker of the flat rails and in the channel?
E. g. if you want overall a 30mm rocker (compared to the centerline rocker of a v-bottom without channel), do you 25mm on the rails and 35mm in the channel?
Gernerally, is there more rocker in the channel or less rocker in the rails compared to a V-bottom?
I guess to compensate the flatter rail rocker in a a channel tail you need more centerline rocker for tight turning.
So to do a tight turn on a board with channel tail you have to push the tail with the backfoot and with a v-bottom you do a tight turn more on the rail / frontfoot because there is the rocker?
Maybe someone how has riden the different Simsup L41 models, which switch from V-bottoms to channel bottoms, and could tell the difference.
Alex
