Questions about patrol

[SteamWake]

The biggest 'trick' is to get well ahead of the targets apparent course so that you can close to within 2,000 yards at a more or less 90 degree angle to their course and lay in wait.

In other words let them come to you. If they are already moving away it most likely is too late. You will simply burn up too much fuel trying to chase it down.

As to the last question I stay on patrol till either the torpedoes or ice cream runs out.