I'm really interested in the nuts and bolts of U-boat tactics and considerations. I can't find anything about real encounters, the distances/times involved, what parties did and why. I've watched most of what I can find and it doesn't really explain it to me.
I'd love something that can describe in detail an encounter from first sighting. Things like, why did the boat do this? Was it surfaced, submerged, how deep? What could they infer from sensors? If they were hunted by the enemy, how and why did it go down?
There was a WW2 infantry doco I watched a little while ago which had kind of what I wanted. I forget the name, but they used the Red Orchestra engine to simulate visuals for the battles. It paced out the fight, how it went and why. I would really enjoy something like that for naval stuff.
I don't know of any sources that offer an inclusive play-by-play, but the USN deck logs or War Diaries often contain such detail. NARA II in the Washington DC area has most of the surviving logs, but you might also have some luck with Fold3 depending on what you're looking for: here's part of a War Report for DE-189 Bronstein when she participated in the sinking of U-801 that I found on their site (note: I have a subscription):
Narrative of Action.
0717 GCT Set course 242°T, speed 20 knots.
0737 Changed oourae to 190°T.
0741 Changed course to 170°T.
0816 Joined CORRY, taking position 2500 yards on COREY's port beam, base course 180OT, speed 15 knots. Conducting box search for enemy submarine, CORRY in. tactical command.
0825 Unit changed course to 270°T using reflection turn, bringing BR0NSTEIN on CORRY's starboard beam.
0921 Unit changed course to 000°T using reflection turn, bringing BRONSTEIN baok to CORRY port beam.
0930 Aircraft observed 350°T, distant seven miles, circling continuously over the same position.
1020 Aircraft dropped smoke flares, at intervals, along a track 340°T.
1023 Plane requested unit, by voice radio, to investigate oil slick marked by smoke flares.
1031 Following movements of CORRY, proceeding down oil slick, CORRY to right and BRONSTEIN to left of slick, course 340°T, speed 15 knots.
1038 Changed course to 330°T, speed 10 knots, as the end of the slick was approached.
1042 BRONSTilN established Sonar contact bearing 015°T, range 1800 yards. Came right to that course, maintained speed 10 knots. Sound contact identified as submarine by width of target, nature of eoho, recorder traces, moderate down doppler, and range rate of seven knots. Plot showed submarine moving away from ship and turning left slowly. Bearing now 050°T and drawing left slowly. CORRY ceased echo range and stood by.