12.1 The weather deck on all vessels shall be
watertight or fitted with closures to ensure watertight integrity.
The drainage from the weather deck shall be such that the watertight
integrity is not compromised.
12.2 When a deck is fitted with bulwarks such
that shipped water may be trapped, the bulwarks shall be provided
with efficient freeing ports.
12.3 The area of freeing ports shall be at least
5% of the bulwark area and be situated in the lower third of the bulwark
height, the bottom of which shall be flush with the deck.
12.4 A vessel of less than 12 m in length, certified
to operate in coastal waters, having a well deck aft and is fitted
with bulwarks all round and which always operates with stern trim,
may be provided with a minimum of two ports fitted (one port and one
starboard) in the transom, each having a clear area of at least 225
sq.cm.
12.5 Where a non-return shutter or flap is fitted
to a freeing port it shall have sufficient clearance to prevent jamming
and any hinges shall have pins or bearings of non-corrodible material.
Normally, hinges shall be along the upper edge of the non-return
shutter or flap.
12.6 Where a vessel has side deck areas of less
than one-tenth the length of the vessel, in which water can be trapped
a smaller freeing port area may be accepted. The reduced area shall
be based on the volume of water, which is likely to become trapped.
12.7 In a vessel in which freeing ports cannot
be fitted, other efficient means of clearing trapped water from the
vessel shall be provided to the satisfaction of the Administration.
12.8 Structures and spaces considered non-weathertight
shall be provided with efficient drainage arrangements.
12.9 Where cargo is to be stowed on deck the stowage
arrangement shall be such as to not impede the free flow of water
from the deck.