This is based on the Solitaire Battleship puzzle that has appeared in Games magazine. I wanted to create an online version of it, but I did not get past making this. It generates a new puzzle with the ships filled in. Unfortunately, the puzzles it generates are not guaranteed to be solvable.
Solitaire Battleship is a game where you start with a blank grid with a number beside each row and column. The numbers tell you how many squares in that row or column are occupied by a boat. There is one battleship on the board, which is four squares long. There are two cruisers on the board, which are three squares long. There are three destroyers on the board, which are two squares long. There are four submarines on the board, which are one square in size. Ships can be aligned horizontally or vertically -- never diagonally. No boat can be adjacent to another boat, even diagonally.