No watercraft which has in tow or shall be otherwise assisting a person on water skis, aquaplane, surfboard or similar contrivances shall be operated or propelled in the waters of the City unless such watercraft shall be occupied by at least two competent persons, an operator and an observer; provided that this subsection shall not apply to watercraft used in duly authorized water ski tournaments, competitions, expositions, or trial therefor. (Ord. 1851 § 11, 1995: Ord. 1277 § 3, 1985: Ord. 377 § 20 (a), 1965).