As I see it, as a layman, If you have a sailing boat and install a motor in it, the sail should be taken down if the motor pushes the boat over the wind speed. At that point, the sail would only start to cause significant drag. Obviously the boat can't reach the speed of the wind using sails alone, as there's always friction (drag in water and air) to fight against, so technically one can use a motor to give a little bit of extra push without turning the sail into a drag chute.
All that being said, it's obviously an F rank boat if it can't carry a tiny shark.