I was just wondering if there are any real advantages in making ply boards hollow rather than just gluing the deck peice and the bottom peice directly together.
You can reduce weight, without reducing 'floatability'.
Strength is not really a problem. and you can always reinforce with some glassfibers and polyester or resin.
One more thing, what gives better upwind ability, a squarish board or a more elliptical shape. And which is better for waves (where i do most of my riding).
Squarish is good for upwind, elliptical for waveriding.