303. Duration of certificates.- (1) A safety equipment certificate, a qualified safety equipment certificate, an equipment certificate and a qualified equipment certificate issued under this Part shall be in force for twenty-four months from the date of its issue or for such shorter period as may be specified in the certificate. (2) Any certificate issued under this Part not specified in sub-section (1) shall be in force for twelve months from the date f its issue or for such shorter period as may be specified in.the certificate. (3) The Central Government or any person authorised by it in this behalf may grant an extension of any certificate issued under this Part in respect of an Indian ship for a period not exceeding one month from the date when the certificate would but for the extension have expired, or if the ship is absent from India on that date, for a period not exceeding five months from that date. (4) Notwithstanding anything contained in this section a certificate issued under this Part shall not remain in force after notice is given by the authority issuing the certificate to the owner or master of the ship in respect of which it has between issued that that authority has cancelled the certificate. | 
