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USCG Marine Safety Alert 1-08
Assistant Commandant for Marine Safety, Security and Stewardship
May 9, 2008

Washington, DC

Maintaining Vessel Watertight Integrity

This Safety Alert addresses two issues: watertight integrity and high level
bilge alarms.

Recently a marine casualty involving a fishing vessel in the Bering Sea
resulted in multiple fatalities and complete loss of the vessel. A Marine
Board of Investigation is currently examining the various circumstances
surrounding the casualty. Although the investigation is not complete,
testimony indicates the flooding of the vessel may have been exacerbated
due to open or leaking watertight doors and other compartmental deficiencies
which impacted the vessel’s overall watertight integrity.

As a result of this and other similar casualties, the U. S. Coast Guard
strongly recommends vessel owners and operators:


Ensure all watertight decks and bulkheads are inspected periodically to
verify that there are no unprotected openings or improper penetrations that
will allow progressive flooding and that closure devices (e.g. watertight
doors, duct closures, etc.) are in place and in working order.

Ensure all crewmembers are familiar with the locations of the watertight
doors (WTDs) and weather tight closures throughout their vessels. Knowing
the locations of such WTDs and weather tight closures should be part of the
crewmember vessel familiarization process.

Ensure WTDs and hatches are closed while at sea and as otherwise specified
in the stability guidance provided to the master or individual in charge.
The importance of keeping WTDs and hatches closed should be emphasized on a
regular basis (e.g. at safety meetings). WTDs and hatches should be opened
only briefly to allow passage and labeled appropriately to remind
crewmembers to close them. If they must remain open to permit work, WTDs
and hatches should be attended at all times so that they can immediately be
closed. Any WTDs permitted to be open while the vessel is underway should
be secured during drills to ensure they work properly.

Implement a WTD inspection program to ensure each WTD is regularly
inspected and properly maintained. As part of the inspection of each WTD, the
following should be examined: straightness of the knife edge; the door
assembly for twisting or warp-age; evidence of loose, missing seized or
damaged components; permanent set in gasket material, cracks in the gasket;
gaps at gasket joints; paint, rust, or other foreign material on gaskets,
knife-edges and working parts; binding and difficult operations; and loose
or excessively tight dogs. Rotating spindles of the dog, handles and
hinges, and other points of friction should be lubricated to prevent seizing and
allow proper closure. If fitted, the spindle packing should also be

Ensure watertight hatches, dogged manholes, bolted manhole covers, and
access plates are given similar examinations, focusing on the sealing
surfaces and the method by which the hatch is secured. Gasket materials
should be replaced whenever they are found insufficient. Regardless of the
type of hatch or access, every component that secures the device, such as
dogs, wing nuts, or bolts should be inspected, lubricated and free, and
repaired or replaced as necessary to ensure they operate properly. As with
watertight doors, hatches and accesses should be labeled to indicate they
remain closed while underway. Most importantly, all securing devices must
be used when the hatch or access is closed. Improper closure of a hatch
will not prevent flooding.

Ensure compartments and external hull structures fitted with ventilation
ducts that have hinged covers with gaskets, hinges, sealing surfaces and
securing mechanisms are regularly inspected and properly maintained (see
above for guidance).

Ensure electrical cables and conduits, piping runs, remote valve actuators,
and other components that penetrate watertight bulkheads, decks, and
compartments are inspected frequently and properly maintained. Each may
have a unique sealing method involving glands with packing assemblies,
penetration seals, or other methods. Frequent inspection and proper
maintenance of these various fittings and assemblies will assist in
minimizing the possibility of progressive flooding.


Ensure water accumulation is minimized and all spaces are kept dry unless
permitted by the stability instructions provided to the master or
individual in charge.

Ensure bilge high level alarms are arranged to provide the earliest
warnings of abnormal accumulation. The high level bilge alarms should be set as low
as possible to the deck or bilge well and positioned along the centermost
area of the compartment or in a location at which the fluids will gravitate
to first. In areas where bilge water routinely accumulates, the bilge high
level alarms should be placed just above the point where under normal
working conditions the accumulation would be pumped to a holding tank,
overboard, or through an oily water separation system if required. Alarms
may be fitted with short time delays to prevent nuisance alarms caused by
the rolling and pitching of the vessel.

Ensure all crewmembers understand the importance of minimizing water in the

Provide the funding, labor, spare parts, and vessel availability necessary
to ensure leakages stemming from machinery, equipment and other components
are kept to a minimum at all times in accordance with good marine practice.

This safety alert is provided for informational purposes only and does not
relieve any domestic or international safety, operational or material
requirement. Developed and distributed by the Office of Investigations and
Analysis, United States Coast Guard Headquarters, Washington, DC.


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