Section 28(4)(c) in The Merchant Shipping (Prevention of Pollution by Oil from Ships) Rules, 2010
(c)the buoyancy of any superstructure directly above the side damage shall be disregarded and the unflooded parts of super structures beyond the extent of damage may be taken into consideration provided that they are separated from the damaged space by watertight bulkheads and the requirements of clause (a) sub rule 3 above in respect of these intact spaces are complied with and hinged watertight doors may be acceptable in watertight bulkheads in the superstructure;