section provides for consideration of the risks of
green water being shipped aboard and the resulting
consequences with respect to the vessels stability
and safety of personnel on deck.
6.1 The standards
for water freeing arrangements should comply with ICLL as far as it
is reasonable and practicable to do so.
In any case the intention should be to achieve a standard of
safety which is at least equivalent to the standard of ICLL.
Additionally, where a well is created on each side of the
vessel between a superstructure or deckhouse, and the bulwark in way
of that superstructure or deck house, the following formula may be
used to determine the required freeing port areas on each side of
the vessel for the well concerned:
On sailing vessels, where the solid bulwark height does not
exceed 150mm, specific freeing ports, as defined above, are not
6.2 In individual cases, when the
Administration considers that the requirements of ICLL cannot be
met, the Administration may consider and approve alternative
arrangements to achieve adequate safety standards. Freeing
arrangements may take account of a reduced permeability and volume
of the well, when compared to a full size well.
In considering an individual case, the Administration will
take into account the vessels past performance in service and the
declared area(s) of operation and any other conditions which
restrict the use of the vessel at sea which will be recorded on the
load line certificate issued to the vessel. (See section
6.3.1 Any recess in the weather
deck should be of weathertight construction and should be self
draining under all normal conditions of heel and trim of the
A swimming pool or spa bath open to the elements should be
treated as a recess.
6.3.2 The means of drainage
provided should be capable of efficient operation when the vessel is
heeled to an angle of 100 in the case of a motor vessel (see 10A.2),
and 300 in the case of a sailing vessel.
The drainage arrangements should have the capability of
draining the recess (when fully charged with water) within 3 minutes
when the vessel is upright and at the load line draught. Means
should be provided to prevent the backflow of sea water into the
6.3.3 When it is not practical to
provide drainage which meets the requirements of 6.3.2, alternative
safety measures may be proposed for approval by the Administration.
Where the above requirements for quick drainage cannot be met, the
effect on intact and damage stability should be considered taking
into account the mass of water and its free surface