Merchant Shipping Act (Cap. 234), article 200

200. A Maltese seaman who has in his possession more than one Maltese seaman’s card or holds, in addition to a Maltese seaman’s card, a distinctive seaman’s document of identity issued under the authority of the Government of any foreign country, shall without delay and in person produce such cards and documents of identity to the Registrar-General and shall surrender to him such one or more of the cards being Maltese seaman’s cards as the Registrar-General shall require. Surrender of card on ceasing to be a Maltese seaman.