Lobster Boy by Rodman Philbrick

Skiff Beaman has a problem. A BIG problem.
 
He needs to fix up his family's fishing boat, but to do that he needs money. A whole heap of money.
 
His father isn't going to help - he can't see further than the next can of beer since Skiff's mother died, and nor is his classmate, Tyler, invertor of the nicknam "Lobster Boy".
 
But Skiff can still hear his mother's voice telling him "Never give up". So he comes up with a plan. It's crazy, it's dangerous and it's going to take all Skiff's grit and strength to win a great battle against the sea.