(a) It shall be unlawful for any person to engage in skin diving or underwater diving requiring apparatus for underwater breathing or to engage in any other under water activity requiring such breathing apparatus in said entrance channel except that diving for salvage or recovery purposes may be authorized upon written permit of said Harbor Patrol.
(b) When a person or persons are engaged in an underwater diving activity, there shall be present an attendant not less than sixteen (16) years of age who shall be on the surface of the water close over the person or persons engaged in the underwater activity, and such attendant shall conspicuously display the “Divers Flag” during diving activities.