A motorboat shall not be required to be numbered under this article if it is:
(1) Already covered by a number in full force and effect which has been awarded to it pursuant to federal law or a federally approved numbering system of another state: Provided, That the boat shall be registered in the state of principal operation;
(2) A motorboat from a country other than the United States temporarily using the waters of this state; or
(3) A motorboat used exclusively for racing while participating in races, and the preparation therefor, which have been authorized pursuant to the provisions of §20-7-20 of this code.