2.6.1 All doorways and other openings through
which water can enter into the hull or deckhouses, forecastle, etc.,
should be suitably closed in adverse weather conditions and accordingly
all appliances for this purpose should be maintained on board and
in good condition.
2.6.2 Weathertight and watertight hatches, doors,
etc., should be kept closed during navigation, except when necessarily
opened for the working of the ship and should always be ready for
immediate closure and be clearly marked to indicate that these fittings
are to be kept closed except for access. Hatch cover and flush deck
scuttles in fishing vessels should be kept properly secured when not
in use during fishing operations. All portable deadlights should be
maintained in good condition and securely closed in bad weather.
2.6.3 Any closing devices provided for vent pipes
to fuel tanks should be secured in bad weather.
2.6.4 Fish should never be carried in bulk without
first being sure that the portable divisions in the holds are properly
installed.
2.6.5 Reliance on automatic steering may be dangerous
as this prevents ready changes to course which may be needed in bad
weather.
2.6.6 In all conditions of loading necessary care
should be taken to maintain a seaworthy freeboard.
2.6.7 In severe weather, the speed of the ship
should be reduced if excessive rolling, propeller emergency, shipping
of water on deck or heavy slamming occurs. Six heavy slammings or
25 propeller emergences during 100 pitching motions should be considered
dangerous.
2.6.8 Special attention should be paid when a
ship is sailing in following or quartering seas because dangerous
phenomena such as parametric resonance, broaching to, reduction of
stability on the wave crest, and excessive rolling may occur singularly,
in sequence or simultaneously in a multiple combination, creating
a threat of capsize. Particularly dangerous is the situation when
the wave length is of the order of 1,0 to 1,5 ship's length. A ship's
speed and/or course should be altered appropriately to avoid the above-mentioned
phenomena.footnote
2.6.9 Water trapping in deck wells should be avoided.
If freeing ports are not sufficient for the drainage of the well,
the speed of the ship should be reduced or the course change, or both.
Freeing ports provided with closing appliances should always be capable
of functioning and are not to be locked.
2.6.10 Masters should be aware that steep or breaking
waves may occur in certain areas, or in certain wind and current combinations
(river estuaries, shallow water areas, funnel shaped bays, etc.).
These waves are particularly dangerous, especially for small ships.
2.6.11 Use of operational guidelines for avoiding
dangerous situations in severe weather conditions or an on-board computer
based system is recommended. The method should be simple to use.
2.6.12 Dynamically supported craft and high-speed
craft should not be intentionally operated outside the worst intended
conditions and limitations specified in the relevant certificates,
or in documents referred to therein.