For the sea model, I wrote a shader that just generates/samples some pseudo-random noise; It was absolute hell trying to sync it with the CPU side of things so that the ship's buoyancy responded correctly. Unfortunately, the web export kinda messes with the sync in some places (level 5 especially), but it's not game-breaking.
We didn't have much time to play-test, since the scope was quite big, so that's the reason for all the rough edges. It's a shame you don't like the sealions, though; they were one of my favourite parts.