PA Title 30, 5123(a), 105.3 Unacceptable Boating Practices
(1) Operate a motorboat at greater than slow, no wake speed with a person riding outside the passenger carrying area or while a person is riding on bow decking, gunwales, transom or motor cover. It is not a violation of this paragraph to ride on the motor cover of an inboard motorboat while underway at that speed if the motor cover is designed by the manufacturer for the operator or a passenger to ride on it. For the purposes of this paragraph, the passenger carrying area is defined as the space intended by the manufacturer for persons to sit or stand while the boat is underway. This prohibition does not apply when the operator of the boat is docking, mooring, anchoring or rafting the boat.
This is from Pennsylvania law but your state may be different. I do not think that if I wrote a citation under this section of the law it would hold up in court even at above no-wake speed. At no wake no case.