In the interest of safe navigation, life, safety and the protection of property, the chief of police shall designate restricted areas, and the purpose for which the same shall be used. No person shall operate a vessel or watercraft within a restricted area; provided, that this section shall not apply to watercraft engaged in or accompanying the activity to which the area is restricted, nor to patrol or rescue craft or in the case of an emergency. [Code 1980 at § 10.12.140].