Hello everybody
I’m always super fascinated about bottom contours, latly i found this picture, and i’m corious houw you call this, element, and what does it. So my thought was also same as it shorten the rail lines and kind give hold trough the water travel longer?
Those channels on the rails, I’ve noticed those on some of Bert Burgers SUPs.
1 Like
Doesn’t do squat.
2 Likes
Glasser nightmare . I bet the more it do is satisfay shaper ego. 
2 Likes
Just checked.
Sunova (@Bert_Burger) does have 2 SUP models with similar rail cavities/grooves — the Speed and the Creek (image of the Speed below).
In the past, Bert has had fairly logical reasons for things.
But any substantial hydrodynamic advantage for those rail/tail grooves is not obvious to me. Might create some areas of “slight” pressure difference (?). Changes planing surface geometry in the tail?
1 Like
Could it be also the tail has les volume so the tail sink more?
You can cut or shape a tail with less volume without putting a bunch of divots in it. Most channel bottoms etc between fins do very little. Gimmicks.
2 Likes
The area on a boards rail in front of the side fins where it transitions from a tucked to hard edge is so vital in blending hold and release and has a huge impact on how a board feels. A great shape can be a dog if that hard edge is to far forward or back I think it would be way more beneficial to spend time trying to really dial in that transition and hard edge placement on your shapes. But experimenting never hurts and you’ll learn something from it I’m sure.
1 Like
Think the same. Small mellow channels around fins mostly stiffen skin, not a bad thing.
For sure, that’s why i try to keep it right by going “simple” but clean.
1 Like
Simple and clean. An established bottom and easy to shape, a clean look and not a glass shop nightmare. Single Concave to Double Concave under rear foot or through fins, slight V at center fin. Proven design. Any single element of these three works on its own, but when combined it’s the best in the business.
1 Like
Many, many moons ago-
Some, not all, Greg Noll Cats featured some narrower channels in the back third of the board that were parallel to the centerline. The idea being that you’d generate lower pressure to suck the tail down and let you do noserides.
Yeah, well, I dunno how well they worked nor how they affected how the board turned, I’d think it would make it slower just through induced drag.
Right at the tail? It would suck the tail down and affect how it tracked and turned.
Dunno. Build one with the channels and one without, try them and see, otherwise we’re just waving our hands in the air and guessing.
And then we’ll all learn something. Good luck-
doc…