[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR171.150]

[Page 143-144]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 171--SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS--Table of Contents
 
                  Subpart H--Drainage of Weather Decks
 
Sec. 171.150  Drainage of a vessel with a well deck.

    (a) Each well deck on a vessel must be watertight.
    (b) Except as provided in paragraphs (c) and (d) of this section, 
the area required for freeing ports in the bulwarks that form a well 
must be determined as follows:
    (1) If a vessel operates on exposed or partially protected waters, 
it must have at least 100 percent of the freeing port area derived from 
table 171.150.
    (2) If a vessel operates only on protected or partially protected 
waters and complies with the requirements in the following sections for 
a vessel that operates on exposed waters, it must have at least 50 
percent of the freeing port area derived from table 171.150:
    (i) The intact stability requirements of Sec. 171.030 or 171.050 and 
Sec. 171.170.
    (ii) The subdivision requirements of Sec. 171.040, 171.043, or 
171.070.
    (iii) The damage stability requirements of Sec. 171.080.
    (3) If a vessel operates only on protected waters, the freeing port 
area must be at least equal to the scupper area required by 
Sec. 171.145(d) for a cockpit of the same size.
    (c) The freeing ports must be located to allow rapid clearing of 
water in all probable conditions of list and trim.

[[Page 144]]

    (d) If a vessel that operates on exposed or partially protected 
waters does not have free drainage from the foredeck aft, then the 
freeing port area must be derived from table 171.150 using the entire 
bulwark length rather than the bulwark length in the after two-thirds of 
the vessel as stated in the table.

                              Table 171.150
------------------------------------------------------------------------
                                                           Freeing port
     Height of solid bulwark in inches (centimeters)       area \1\ \2\
------------------------------------------------------------------------
6(15)...................................................         2(42.3)
12(30)..................................................         4(84.7)
18(46)..................................................        8(169.3)
24(61)..................................................       12(253.9)
30(76)..................................................       16(338.6)
36(91)..................................................       20(423.2)
------------------------------------------------------------------------
\1\ Intermediate values of freeing port area can be obtained by
  interpolation.
\2\ In square inches per foot (square centimeters per meter) of bulwark
  length in the after \2/3\ of the vessel.


[CGD 85-080, 62 FR 51354, Sept. 30, 1997]