No person under the age of sixteen (16) years shall be allowed on the dock and floats, or in the boat harbor, unless in the company and under the control of such person’s parent or guardian or some other person over the age of nineteen (19) years having the supervision and control of such person under the age of sixteen (16) years, and for the time and place exercising the responsibilities of such person’s parent or guardian. A person between the ages of sixteen (16) and seventeen (17) years may apply to the port director and for good cause shown shall be granted a permit to go on the dock and floats or in the boat harbor by themselves. Such permit may be restricted and conditioned as, in the judgment of the port director, is warranted by circumstances. Such permit shall be revocable by the port director if the permittee abuses the privilege of access to the port facilities. Good cause for the purposes of this section shall consist of: