I hear you, man! The only thing I can advise is to find a trawler you can shadow and hide under. But even if you do, you still might find yourself under fire. Otherwise move as slow, deep and silent as you can - and steer as far away from warships as possible, even if it means temporarily moving away from the target. Liberal use of time compression helps. Maybe fire a decoy in some random direction too, for good measure.
Good luck, and good hunting!