Section 171.122 - Watertight integrity above the margin line in a vessel of 100 gross tons or more(a) For the purpose of this section, a partial watertight bulkhead is one in which all portions are not watertight.(b) Except as provided in paragraph (d) of this section, the bulkhead deck or a deck above it must be weathertight.(c) Partial watertight bulkheads or web frames must be located in the immediate vicinity of main transverse watertight bulkheads to minimize as much as practicable the entry and spread of water above the bulkhead deck.(d) If a partial watertight bulkhead or web frame is located on the bulkhead deck in order to comply with paragraph (c) of this section, the joint between it and the shell and bulkhead deck must be watertight.(e) If a partial watertight bulkhead does not line up with a main transverse watertight bulkhead below the bulkhead deck, the bulkhead deck between them must be watertight.(f) Each opening in an exposed weather deck must-(1) Have a coaming that complies with the height requirements in table 171.124(d); and(2) Have a means for closing it weathertight.(g) Each port light located between the bulkhead deck and the next deck above the bulkhead deck must have an inside dead cover than can be secured watertight.CGD 79-023, 48 FR 51017, Nov. 4, 1983, as amended by CGD 85-080, 61 FR 945, Jan. 10, 1996; 62 FR 51354, Sept. 30, 1997