I had a portable talking version of battleship (Battleship Command) as a kid and it has these little planes. If I remember correctly, I think they allowed you to "see" a little bit of the opponents board and you placed them on top of your own ships?

Also the sound effects in that version were great, almost all done by human voice. The ship sinking sound was hilarious "glub glub glub"

Edit: in fact, this picture definitely looks like it's from Battleship Command!