Each watertight subdivision bulkhead, whether transverse or longitudinal, shall be constructed in such a manner that it shall be capable of supporting, with a proper margin of resistance, the pressure due to the maximum head of water which it might have to sustain in the event of damage to the ship but at least the pressure due to a head of water up to the margin line.
Where in a portion or portions of a ship the watertight bulkheads are carried to a higher deck than in the remainder of the ship and it is desired to take advantage of this higher extension of the bulkheads in calculating the floodable length, separate margin lines may be used for each such portion of the ship...
Water bulkheads extending to the deck or, in the absence of a deck, to the upper edge of the hull planking or plating must be installed as follows:
(a) a collision bulkhead at an appropriate distance from the stem;
(b) in vessels whose length overall is over 25 m, a stern bulkhead at an appropriate distance from the stern.
