You can simply drag a waypoint somwhere on the map, look if any contacts will be near there and then just set course. It pretty much an easy mode. From time to time BDU sends a sitrep where enemies were spotted and then you can plot your course to the direction and start tracking them.
Full Answer
Passive abilities include a faster reload speed, a lower chance of dud torpedoes, and an increase of torpedo range and damage.
This part of the submarine has three levels – the top of the conning tower which is outside and contains the UZO (functionally a periscope), the attack periscope which is in the second level of the conning tower, and the observation periscope which is in the command room.
The Executive Officer (XO) has the active abilities to call battle stations, and rig the boat for silent running. The Navigator has the passive abilities to increase the operating depth of the submarine, make surfacing and diving happen faster, and to maneuver the submarine faster.
To accurately fire a torpedo a submarine needs to know the torpedo's speed, the target's speed and heading, and the submarine's speed and heading, and the distance to target. The following steps will acquire all the required info.