Subject to the provisions of sections 83 and 84, a master, ships’ officer or rating shall not be deemed to be duly certificated as such for the purposes of this Act, unless he is the holder for the time being in the case of a -
(a) master or ships’ officer, of a valid certificate of competency or certificate of service, issued in terms of this Act, of a grade appropriate to the ship in which he is employed and to his station in the ship, or of a higher grade; or
(b) rating, of a valid certificate of qualification, issued or recognised in terms of this Act.
