What has hit me?

[Ford Prefect]

you could solve this issue by opening the main game files in the mission editor, finding the area you were in, if there is a mine field there you can check the depths of the mines with in it.

Originally Posted by Lt.Fillipidis

Hmm...
Theory No.1 is a no go since the SH3 sea bed is as flat as the surface in a shiny, 0wind day. The only thing changing its shape would be the uboat.

out away from the coast it's flat aye, but close in around scotland I've seen plenty of undulations in the sea floor and nearly ran aground myself.