Height of rails and bulwarks
25.—(1)  When rails and stanchions are fitted to any deck or superstructure to which passengers are admitted the top of the uppermost rail shall not be less in height than 3 feet 6 inches above the top surface of the deck or superstructure at the inner edge of the waterway and the rails shall not be more than 9 inches apart, unless strong netting is provided to the satisfaction of a surveyor of ships. Provided that in passenger ships not going on voyages beyond the 30 mile limit, the height of the rails may be reduced to 3 feet.
(2)  When close bulwarks are fitted they shall be at least 3 feet 6 inches above the top surface of the deck or superstructure at the inner edge of the waterway and the freeing ports shall be fitted with grids to the satisfaction of a surveyor of ships. Provided that in passenger ships not going on voyages beyond the 30 mile limit, the height of the bulwarks may be reduced to 3 feet.