4.—(1) A ship shall be measured by a surveyor.
(2) The gross and net tonnages shall be determined in accordance with regulations 6 and 7 provided that in the case of novel types of craft with constructional features which render the application of the provisions of these Regulations unreasonable or impracticable, the gross and net tonnages shall be determined as required by the Secretary of State.
(3) All measurements used in the calculations of volumes shall be taken and expressed in metres to the nearest one hundredth of a metre.
(4) Gross and net tonnages shall be expressed as whole numbers, decimals being rounded off downwards.