Section 171.140 - Drainage of a flush deck vessel(a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be watertight and have no obstruction to overboard drainage.(b) Each vessel with a flush deck may have solid bulwarks in the forward one-third length of the vessel if-(1) The bulwarks do not form a well enclosed on all sides; and(2) The foredeck of the vessel has sufficient sheer to ensure drainage aft.CGD 85-080, 62 FR 51354, Sept. 30, 1997