Bevelled vs hard rails

KT, Dave Kalama and Jimmy Lewis all well understand that sharper rails produce water release and rounder rails produce control through the water with water following the rail or sucking as some people on here like to call it. They have been using this understanding and balancing its subtleties for decades to get surfboards to work well in turns and on a steep wave. In fact this is the basis for design (physics) in all naval architecture for at least 100 years and can be seen in both displacement and planning hulls but is more critical in foils and propellers where water is moving at higher velocities. Think water ski's, speed record setting windsurfers, pipeline surfboard guns and particularly fins where control or release is a higher priority.

A cutback on a surfboard uses the softer rails around the front foot to allow the board to engage with the water and provide some control into the turn buy grabbing the water (sucking) and as we complete the turn we transition to the back foot where the rails are sharper and this allows us to pull out of the turn by releasing the water from the sharper rail on the tail. The best foil surfers like surfboard rails (soft) around their front foot because in white water hits where the foil become inactive you want the board to provide control in the foam so some sucking is good. Again subtle and a balance. Now introduce the fact you are touching down from a foiling turn and the foil is still mostly in control but needs some temporary support (control) but not too much. Some might like more support by sacrificing release. I learnt to foil by mounting a foil to a twin tip and the sharp edges provide no control before being on foil as it releases on the whole edge as designed and definitely can't track to give support so no directional stability.

I am not disputing what you are all feeling and enjoying in the boards that favor your style and circumstances but its not because of the design elements you might think. Rails, bottom surfaces, rocker line, volume, volume distribution, flex are all working together to balance release and control at different speeds angles and circumstances.

Taavi you board works better (releases) standing further back because you are likely engaging less of the round sucky rail and bottom shape.

Keeping the thread alive. Stumbled upon yet another board with a nice shape, with displacement style nose and round rails going pretty far until the shape turns into having more flatter surfaces in the back. Nicely pulled in nose and tail. I wonder why brands keep coming up with such designs, if people with no experience riding with such shapes find such rails and bottom shapes "sucky" and not good "because of physics".