Five ships fill 17 cells: a 5-cell Carrier, a 4-cell Battleship, a 3-cell Cruiser, a 3-cell Submarine and a 2-cell Destroyer.
Every fleet in Naval Battle has the same five ships, which together cover 17 cells of your 10×10 grid.
- Carrier: 5 cells.
- Battleship: 4 cells.
- Cruiser: 3 cells.
- Submarine: 3 cells.
- Destroyer: 2 cells.
Why the sizes matter
A ship is sunk when every one of its cells is hit, so the 17 cells are also the number of hits you need to win (how to win Naval Battle). Knowing which ships are still afloat tells you how big a gap on the grid can still hide one: a gap two cells wide can only hold the Destroyer.
The Naval Battle strategy guide shows how to use the sizes when you search, and how to play Naval Battle covers the rest of the rules.