No person shall install or use any intermittently flashing light of any type or color on any watercraft in use or operation on the waters of the City, except that such flashing lights may be installed and used in an emergency to attract attention to such an emergency for aid and relief of the distressed, and except that a blue colored revolving or flashing horizontal beam of low intensity located at any effective point on the forward exterior of the watercraft may be displayed by authorized patrol boats when engaged in law enforcement duties day or night on waters of this City.  (ORC 1547.03)