While in the boats they will rise out of the water and almost act like it was on a hill as it falls.
The boats don't stay on top the water causing the boats motor to come out of the water but again it seems like it's falling down a hill.
note:
While driving the boats in reverse the boats don't appear to be falling like on a hill as much.
The water also comes through the boats rather than a wave appearing to come over and inside the boats. {F17395}