You can only move your head 180° while in boats. Entering a boat while looking anywhere outside that range will move your head to one of the ends of the 180° range, which is very irritating: You can't move your head in one direction and the way you're facing isn't even the way the boat will be going once you start moving.
I think this is Working As Intended. You will need to use the oars to turn the boat. Admittedly, it's a bit confusing on where your character should be able to turn when you enter the boat, but the rest is okay!