Stopping underwater. Any figure?

[Cpt.Nautilus]

Originally Posted by mpugsley

But surely they could dive to 60m and turn their engines off. The question is just what would happen afterward. So what would happen? Would they start floating to the surface? Were they unable to manage their ballast such that they wouldn't float up (or sink further down)?

It's virtually impossible to completely balance a sub. So, once you can't use the depth planes to control your depth, you are going to either sink or float. However, this should be quite slow and as long as you don't stay for too long, it shouldn't be a problem.

Another problem would be the trim. Again, without speed to control your attitude, your U-boat is goint to pitch up or down, and this may be much more of a problem.

I would be interested to read real figures about these processes. How fast they happen. Could real U-boat stop for a few minutes? And if they could, did they do it actually? If they couldn't, what was the minimum speed needed to steer the boat?