[Dronston]

Patrol 8, january '41. On my way back to Lorient and I'm at the south entrance of the Irish Sea when I stumble upon a large convoy. I have two eels left in the bow and two in the stern so I decide to try and sink the biggest ship in the convoy which happened to be a British tanker. I had to get within 4 km because I only had electric eels. I release the torpedoes and immediately dive to 90 meters (max depth in this area) and switch to silent running. In the same time I return to my Lorient course. With 50 rpm I hope to sneak away but soon I hear the ominous ping of a destroyer and the depth bombing begins. The destroyer asks 2 others for help and now they take turns trying to blast me out the water.

They have been chasing me for over 3 and a half hours now! So far I only sustained minor damage. They don't seem to run out of depth charges and they don't give up. I am used that at some point they will return to the convoy but that must be over 30 km's away now. I am getting close to 50% of my batteries.

My tactic to avoid depth charges is to go at 1 knot and when my hydrophone oprator informs me of charges in the water I go to full speed.
All 3 boats seem to have sonar so I can't sneak away. In the end I will have to surface. For the moment I am going the opposite direction of the convoy in the hope the destroyers will soon return to them.

I am considering to go to periscope depth and try to take out 2 destroyers with my aft torpedoes but I know this means almost certain death and will in the best scenario still leave one destroyer.
Any tips to get out of my situation?