Bulkhead deck is the uppermost deck up to which the transverse watertight bulkheads are carried. <Chapter II-2, part A, regulation 3>.
Source: IMO Resolution MSC.99(73), amendments to the International Convention for the Safety of Life at Sea, 1974, as amended, 5 December 2000, International Maritime Organization. Legislation
Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which passenger and crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter. The bulkhead deck may be a stepped deck. In a cargo ship the freeboard deck may be taken as the bulkhead deck. . <Chapter II-1, regulation 2>.
Source: IMO Resolution MSC.216(82), amendments to the International Convention for the Safety of Life at Sea, 1974, as amended, 8 December 2006, International Maritime Organization. Legislation