37. Watchman or person on board
(1) Between sunset and sunrise, whilst a vessel is occupying a Berth, the Master of the vessel must ensure that ¾
(a) if the vessel exceeds 150 tonnes gross, there is a watchman on board; and
(b) if the vessel does not exceed 150 tonnes, there is at least one person on board.
(2) A Master who contravenes this by-law commits an offence.