54Certificates of Convention ships to be produced to Customs.
The master of every Load Line Convention ship not registered in the United Kingdom shall produce to the officer of Customs from whom a clearance or transire for the ship from any port in the United Kingdom is demanded—
(a)in a case where clearance is demanded in respect of an international voyage, a valid Load Line Convention certificate;
(b)in a case where clearance or transire is demanded in respect of any other voyage, either a valid Load Line Convention certificate or a United Kingdom load line certificate for the time being in force in respect of the ship;
and a clearance or transire shall not be granted, and the ship may be detained, until the certificate required by this section is so produced.