Measurements
9.—(1)  The area of the deck space appropriated to passengers shall be ascertained by Simpson’s first rule, an appropriate number of breadths being taken.
(2)  Each breadth shall be taken between the inner edges of the waterways, ceiling, cargo batten or ships frame whichever breadth is the least, allowing for tumble home at the minimum height of 6 feet if necessary.
(3)  The length of the deck available for measurement is to be taken from and to such points as a surveyor of ships may consider fit for the safe and proper accommodation of passengers. Each breadth shall be taken between the inner edges of waterways, raised covering boards, rails or bulwarks whichever breadth is the least.
(4)  The clear area of a deck space available for passengers is the deck area after all encumbrances such as hatchways, skylights, companions, machinery casings, dunnage, cattle fittings, navigating spaces, windlass, boats carried inboard, etc. are deducted: Provided that on vessels going on voyages to which rule 4 applies, without calling at intermediate ports to work cargo, the hatchways in the spaces occupied by unberthed passengers need not be deducted.