The U-Boat is a few pages back if you want it as well. It has a max speed of 11knts and can submerge up to it's periscope.
Quite fun to just set it on full speed, aim it open sea and leave it for a few hours to see where you get

I'm tempted to leave it on 4x speed when I go on holiday from the 10th-17th of January and see where I end up
