what about the strongest of them all
poor optimization, the legendary beast of the sea
Just use a regular diving kit and use a normal build to kill the sharks 
The problem with that is you can only use 1 other positive potion while you have waterbreathing. You pretty much NEED revealing, and sharkpel would be good since you probably wont have much vision to see where the sharks are
I have lightning charge, which is more efficent lighting than torches.