I've been thinking for awhile about ways to combine these two fun puzzle types - Battleships and Sudoku. I've come up with two variations that fit this theme (three examples of each) - basically differing in whether you consider "ships" to be black squares that do not contain digits, with ship segments distributed a fixed number of times in each row/column/box, or whether you just "number" all the segments in a standard 10-ship battleship fleet and then place them in a sudoku grid.
If you enjoy battleships puzzles, I think you will appreciate the challenge of these. They are posted here on my blog.
Thomas Snyder