I was sad to head the dev of this mod will no longer be working with the water, due to the lack of stuff to do, so i made a list:

1) A block called "100% stable":
this block will allow the creations of water bases that float. The block will have a strong float, allowing heavier metals to float. the more you add, the stronger it is.

2) Water wheel and Water propeller:
These will only work in water, and work much like the real thing.

3) Torpedo:
this will be a modeled block of a torpedo, that will stay a little below water (just enough for the waves to not effect it), and will explode in impact. Their will be diffrent warheads on each, specializing in certain damage. (AP, HE, Incindiary, etc)

This is about all i can think of, lets hope the mod dev decides to add these to his mod once the water comes out to sandbox.