Set a Diver Group with boat in Grid: 022058 and give it a straight move order to Grid: 027061 (X: 2791 Y: 6138 z: 0. It does not seem to matter which direction they are pointing. The boat will normally head towards the pier and get hung up. I have reproduced this several times with the same results. Make sure to set your player as a Diver instead of Driver or Team Leader.

No biggy if this is not fixed but it would be nice to set a boat path like a helicopter or vehicle without using multiple moves. Boats come under more fire each time they slow down to change course. I play Arma because of the realism factor...and boats that slow down under fire is not real unless hit.