[XenonSurf]

For harbor raids: It's adviced to only do the scripted raids that appear as missions on the map (for example Scapa Flow), else stay away from ports because the AI is not intented to combat and track you there, so its performance will be more than bad. Going into ports could even mess-up your campaign in that you may not encounter anymore traffic.


Often use 'Send Contact Report' when you encounter enemy assets (also aircrafts), so the friendly ones have a chance to join the battle which they will do sometimes. You can check the airplane ranges by clicking airports on the map. Other times you are asked to wait for re-inforcements to arrive (wolfpack AI subs) in the case of a convoy.
The downside of using your radio is that enemy is listening too and will certainly send units to your location, so keep attention. Best place to observe this is in the 1st campaign chapter, Coastal Waters, often I don't need to fire a single torpedo, the german planes will do all the job if I send a contact report.

The OH2 campaign included in WoS has a serie of historical additions to the stock game, so there is more traffic in appropriate locations at a specific date to simulate historical events. You will even see units fighting each other.