Naval Command is Yahoo! Games' version of Battleship. In addition to all the standard Battle Ship rules; there are the following variations at Yahoo!:

Extra Turn On Hit
This option allows you to fire again when you hit an opponent ship. Thus it is possible (although highly unlikely without cheating) to win a game on your first turn.
Fire As Many Times As You Have Ships
This option is interesting because as one player starts to sink the other's ships, he also weakens the other player.

Play at: http://games.yahoo.com/games/login?page=flt