Nils has been busy testing the campaign. Here's what happened:
I was tasked with intercepting a landing force bound for Iceland. Having set up a nice forward position through the campaign map, I managed to inadvertently broach the sail getting to periscope depth. That got the attention of the escorts, but since losing Iceland was not an option I decided to brave the gauntlet of RBU barrages, air dropped torpedoes and SS-N-14's before finally managing to hide under this Alligator landing ship. The escorts can be seen in the background looking for me.
The AI will, upon detection, designate a pair of escorts, hunter and killer respectively, and they will work with any aircraft or helicopters that are present. The hunter will track you and relay targeting info to the killer, who will engage you with various weaponry.
We also see the effects of sonar masking where noise from the landing ship is drowning out noise from my Skipjack, providing a place to hide from the escorts.
Unfortunately it was all for nothing... Having lost the initiative and evading the escorts for so long, most landing ships escaped. Sorry Iceland.