Airing space not required
28.  In a shelter deck space, airing space need not be provided if there are clear openings in the ship’s side not less than 2 feet in depth and the areas of the clear opening, or if there is more than one clear opening, on the same side of the space the total area of such openings, on each side of the space shall not be less than the area of an opening 2 feet deep and of a length equal to one third of the length of the space:
Provided that if the openings are closed by watertight shutters, in the manner required to obtain a decreased freeboard assignment, airing space on a weather deck shall be provided for each passenger as required by rules 4, 5 and 6.
The term “space” means that part of the deck between bulkheads, or a combination of side and/or round houses which are equivalent to bulkheads.