Section 27(7) in The Merchant Shipping (Crew Accommodation) Rules, 1960
(7)Every water closet shall be completely enclosed by bulk-heads and shall be provided with exhaust ventilation directly to the open air or to another water close which is provided with ventilation directly to the open air.Provided that a water closet may be separated by a partition consisting of steel or other opaque and rigid material open at top and bottom from -(a)another water closet,(b)a urinal, or(c)washing accommodation if the water closet is served by a trunked mechanical ventilation system which effectively removes odours therefrom.
