Thank you kindly for your comment! Yes, it can be difficult to naviguate, especially if the mouse sensitivity is low on your game (which could be a programming mistake on our end, sorry about that), but part of it is intended as to increase the helplessness of the player for the sake of dread.
As for the monsters having the same appearance as the submarines from far away, it was a very intentional design. It would force the player to be careful, or have a bad surprise!