(3) The owner of every ship in respect of which any such certificate remains in force, shall cause the ship to be surveyed in the prescribed manner at least once in every period of 12 months after the issue of the certificate for the purpose of ascertaining whether the certificate should remain in force, having regard to subsection (2), and if the ship is not so surveyed, the Minister may cancel the certificate, but may, if the Minister thinks fit extend the said period by a maximum of 3 months.