When the boat is about to blow up, it is shown moving slowly towards the shore (from right to left) and a wake is being produced. The outboard motor in the rear is also visible. The camera view then switches to Matlock and Conrad on dry land. But when the camera switches back to the view of the exploding boat, the boat is now fully stopped in the water, no wake can be seen, it's now facing the opposite direction and the outboard motor is missing.