Yes, this is realistic (if you were idle). It's very hard to maintain depth in rough seas in real life if you have no movement either backwards or forward.
On a similar note. I've done a few patrols with the XXI lately. While the 17 knot submerged speed is very useful for catching back up with convoys, it is highly unstable in rough seas. The conning tower pops out of the water constantly.
Also, when surfacing even in calm seas, it first comes up normally, then dive partially under again, and then finally stabilizes on the surface after a few more 'bounces'. But I guess these factors are related to the high speed.
|