An old
board game. Instead of a board though, it had a large roll-out mat. Unfortunately it was very difficult to get this mat flat on most
carpet, and it being flat was very
important to the game. Playing on a tiled or wood floor was easier, but
colder.
The game involved each side having a number of plastic model ships which they set up on this mat. Each ship had rubber bands inside (which the user had to put in and frequently snapped), and the guns and conning tower were pushed in, against this rubber band tension and clipped in. These ships could not be moved once placed by the player.
Each side also had a submarine with a pull back, rubber-band sprung catapult thing. This is much like a pinball plunger and launched discs across the mat. These small 1.5cm or so diameter discs were fired at the opponent's ships from the back of the mat (so you couldn't shoot through your own ships). This seems a bit unrealistic to me now since they were supposed to be torpedos...! The submarine's conning tower consisted of a stack of these discs so about 8 could be launched before they needed re-loading.
Each ship had a slot at 'sea-level' underneath each of its guns and towers. When you managed to lodge a disc in one of these slots on the opponent's ships, the appropriate bit (gun or tower), would fly up and out. When all the sections of a ship had been removed, that ship was removed from the board.
As far as I remember, there were no turns- each player went hell for leather at the opponent with his sub, and the first to destroy all of the opponent's ships, won.
Mat flatness was extremely important because any wrinkles meant the discs flew off at unpredictable angles which made play nigh on impossible.
See also Crossbows and Catapults and Scramble.
Update: Apparently it was a board not a mat. I can't be
100% sure, but I seem to remember there always being
carpet 'issues'. Maybe someone can contribute and correct me...