Regulation 18
If the master of a ship which during its voyage has been in a foreign port cannot produce to the authorised officer for the district in which the ship arrives or for any district at which the ship calls a valid Deratting Certificate or Deratting Exemption Certificate in respect of the ship in the form set out in schedule 3, the authorised officer shall—
if the district is an approved port or a designated approved port, require the ship to be inspected to ascertain whether it is kept in such a condition that it is free of rodents and the plague vector; or
if the district is not such a port, direct the ship to proceed at its own risk to the nearest approved port or designated approved port convenient to the ship at which a Deratting Certificate or Deratting Exemption Certificate, as the case may be, can be obtained.
If, after the ship has been inspected, the authorised officer for the approved port or designated approved port is satisfied that the ship is free from rodents and the plague vector, he shall issue a Deratting Exemption Certificate.
If, after the ship has been inspected, such authorised officer is not so satisfied, he shall—
if the district is a designated approved port, require the ship to be deratted in a manner to be determined by him; or
if the district is not a designated approved port, direct the ship to proceed at its own risk to the nearest designated approved port convenient to the ship for deratting.
If the master produces a Deratting Certificate or a Deratting Exemption Certificate, but the authorised officer has evidence that the deratting was not satisfactory completed or that there is evidence of rodents on board the ship the authorised officer may, notwithstanding such Certificate, exercise in relation to the ship his powers under the last preceeding paragraph.
The master shall forthwith make arrangements for any deratting required by the authorised officer for the designated approved port.
When deratting has been completed to the satisfaction of the authorised officer for the designated approved port, he shall issue a Deratting Certificate.
Before the authorised officer directs under this regulation that a ship shall proceed to another port, he shall consult with a customs officer for the district.