[Corsair]

Well I can tell you when I decided to try and find Lampedusa after 3 full days of estimated plotting, I was feeling a lot of ambiguity.
Using the depth to confirm position is taken from real life, although in these weather conditions on a real boat, I would not even have tried it ( riding a storm with bad visibility is always better far from land...) and I definitely wouldn't have headed for this underwater hill, because the depth going on a short distance from 300m to 30m would IRL induce huge breaking waves and would be a death trap.
Most boats having big trouble in bad weather/visi are those who try to make it to shore as soon as possible when it is in fact safer to stay away from it.. As long as there is water downwind to drift, I stay outside.