- Each transverse and longitudinal watertight subdivision bulkhead shall be constructed in such a manner that it shall be capable of supporting, with a margin of resistance, the pressure due to the minimum head of water which it might have to sustain in the event of damage to the ship. The head of water shall be at least that due to a head of water up to the freeboard deck.
- Steps and recesses in the bulkheads shall be watertight and of strength equivalent to that of the bulkhead.
- Frames or beams that pass through a watertight deck or bulkhead shall be made structurally watertight without the use of wood or cement or any similar material.
- Watertight compartments shall be tested either by flooding or by a hose test at the advanced stage of the fitting out of the ship to establish that the watertight bulkheads are effective.
- The forepeak, double bottoms, duct keels and inner skins shall be tested by flooding with water to the head specified.
- Tanks intended to hold liquids forming part of the subdivision of ship shall be tested by filling with water to a head corresponding to the load line or to two thirds of the depth from the top of the keel to the freeboard deck whichever is the greater, so however that the test head shall in no case be less than 0.9 meter above the top of the tank.
Provided that the head of water specified shall be the highest of the following,
- Head of water upto freeboard deck;
- Head of water upto top of air pipes ;
- Head of water upto 2.5 meters above the top of the tank.