Here’s some more news about Sub Commander. I have added the first enemy submarine. Here’s how it behaves. When attacking, it tries to move to the same depth as the player to fire its torpedos. When both player and enemy are at the same depth, the enemy will fire two unguided torpedos in rapid succession, after wich it evades by either diving or climbing. When it can’t reach firing depth, it will abort the attack and also try to evade.
The player, of course, has to evade the torpedos or shoot them. The most obvious choice are the guided anti-sub torpedos, but unguided anti-ship torpedos can also be used. For this, the player needs to dive below the enemy and aim properly. Here’s a video of some submarine combat:

Yeah, I remembered I had a Youtube account. Totally forgot about that! I’ve used Fraps for recording the video. Great tool for capturing gameplay video and measuring framerates!