depthtok33l, you may try downloading my "
High Realism Tutorial" which gets into manual targeting with the "No map contact update" option selected. This option eliminates the ship silhouette from appearing on the map, making for a much harder (and more realistic) game. You get a 12% increase in "Realism Rating", second only to the 15% increase when selecting Manual Targeting over Auto Targeting.
The Tutorial explains basic Compass information, how the Position Keeper works, and how to plot a targets course on the Navigation Map with only the tools at hand as in real life. The fact is, there was anywhere from 12 to 15 crewmen involved in the "Fire Control Party" (nope, they aren't going to put out a fire.....they planned to make one!). This group is narrowed down to just one player when using 100% realism, so taking some liberty with using the pause game feature should be considered necessary to making a successful attack.
To respond directly to your question about AoB, a map plot will accurately give you AoB of a target if you've determined its estimated range and relative bearing from the subs position. Since your playing with OTC you'll be able to get a good estimate of range with the Stadimeter; using the Range Omnimeter; using Active Sonar; or from the Radar (if available). As was pointed out, taking two or more range and relative bearing readings to the map screen, then marking their position with the pencil, will give you the targets path of travel....which in turn gives you AoB. If you take these readings at a set time interval.....you'll get the targets estimated speed too. All from map plotting.
The Captain may have the ability to estimate these things by pure experience (you too if you play long enough), but he also relied on his Fire Control Party to do the work for him. Since your doing the work of a dozen men, take the time to learn the different aspects of the game which puts you in control of the entire process.
You mention using the crew for information will most always cause your torpedos to miss. Well, that's why you do it yourself. One small point that gets overlooked with a firing solution, whether your using Auto or Manual Targeting, is
open the torpedo doors before firing! The delay that's figured into the solution when you don't have the doors open will cause a miss every time unless you're very close to the target. Always missing to the stern of the target?.....its the doors not opened.