Sub Killer!

You are in command of a Naval Frigate. Below you, numerous submarines lurk, intent on destroying you with anti-ship mines.

It is your job to protect your warship by eliminating the submarines using your proximity-depth charges.

Watch out for the Super Subs. These require a random number of hits to be destroyed. Also note that they are indistinguishable from other submarines.

Try to hit the deeper submarines as these are worth more points.