Russian GSP Ferry (Unit slot 983) has a unit class of 41, Landing Barge and has a speed of 9 and swim of 4.
However, in my running game I placed the ferries on a road to be safe from the watchful eyes of the enemy and to be used in case my opponent destroys the bridge I need for my MBTs. Well, my enemy did use his artillery for that and my ferries still lie there, unable to move to any direction because there's no water hex next to them.
Maybe the vehicle class prevents it from moving on the ground surface even though it has movement points just to do that (and it has tracks IRL). Should the class of the ferry be changed or am I just using it wrong?