4.—(1) Every ship to which these Regulations apply shall carry such number of qualified officers as are required under Part III.
(2) Any certificate required by the Convention to be held by any officer shall be kept available in its original form on board the ship on which the qualified officer is serving.
(3) For the purposes of these Regulations, an officer is qualified if he is for the time being —
(a)
the holder of a relevant certificate of competency issued under these Regulations or a certificate which is treated as equivalent to that certificate by virtue of regulation 8; or
(b)
the holder of a relevant certificate of competency issued by a foreign maritime administration that is recognised by the Director under regulation 9, or in respect of which a certificate of recognition is valid under regulation 10.
(4) In paragraph (3)(a), “relevant”, in relation to a certificate of competency, means the certificate is, at the material time, valid and in force in relation to the person named in it and is of a class appropriate to the capacity in which the holder is to be employed on the ship or of a higher class.
(5) In paragraph (3)(b), “relevant”, in relation to a certificate of competency issued by a foreign maritime administration, means the certificate is, at the material time, valid and in force in relation to the person named in it and is of a grade appropriate to the capacity in which the holder is to be employed on the ship or of a higher grade.