How about a seat on rails with a friction adjustment so that you could slide forward and back in order to drop into the wave and keep it from purling. It'd maybe be awkward at first, but after getting used to, it might work. Shifting the CG a few inches could be useful for other paddling too perhaps.

> It is worthwhile to keep the bow from submerging. It takes a
> lot more force to move a submerged boat through the water than it
> does to move one skimming the surface. A surf boat is basically a
> planing design. A high bow and flat run aft is going to be the easiest
> to surf.

> Some of the effect of a high bow can be achieved by leaning back,
> but it is easier to get started surfing by leaning forward which drives
> the bow down. With the bow submerged you may be slowed enough to be
> pushed off the back of the wave.

> If you want the ability to do front endos, make the bow low volume
> so you can force the bow under when you want to.