(a) The board shall issue a marine pilot license for a marine pilotage region to a person who (1) is a citizen of the United States;
(2) passes examinations that may be required by the board;
(3) has three years experience as a deputy marine pilot licensed under this chapter; and
(4) satisfies additional requirements as may be required by the board by regulation.
(b) Notwithstanding (a) of this section, a person who holds a marine pilot license of any type on the day before July 2, 1991 shall, subject to continued eligibility for the license under this chapter and regulations adopted under this chapter, receive a renewable marine pilot license of the same type and subject to the same qualifications and endorsements as that which the person held on July 1, 1991. A person who receives a license under this subsection may change the type of marine pilot license and the qualifications and endorsements attached to the license in accordance with regulations adopted by the board.