http://www.cyberjoueur.com/java.php?id=19
to play with a person, click on connect and then join someone in the popup menu. but to actually play with them, make sure that you change "Computer" to "Internet", also, if you change num pad to arrows and space it is a lot easier to play, BTW this is 4 players at a time
So great, I'll give more details as soon as battleship is over