I never do harbour raids. i act like a real skipper
i preffer stay in depth waters in front of the port intercepting the traffic.
In real life, a raid could end in a disaster , the crew captured, and the worst, the boat in shallow waters were the divers can enter easily.
Sub nets, sound devices, mines, destroyers with depth charges set to 14-20 meters
air cover ( the boat easy to see in shallow waters),
too dangerous