If you sit in a boat and spin using either the A or D keys and then leave that specific boat, the next time you use the boat it will spin just as fast. Also when you leave the boat while spinning it stops spinning until you get back in. I tested this on all 3 ice's and water. The surface doesn't change anything except it spins at the regular rate for that surface. If you are riding with an entity it doesn't change either. Finally if you switch boats that boat does not spin.