(Ranger Hope © 2008, contains edits of material courtesy of A.N.T.A.  publications)

It is obvious that for a vessel to float, water must be prevented from gaining entry into the hull.  The vessel designer has to ensure that under normal use water will not enter the hull in sufficient quantities to sink it. The shipbuilder ensures that is of sound construction to meet these requirements.  This is verified at the initial survey carried out by an Authority.

It is your responsibility to ensure that your vessel’s watertight and weathertight integrity is maintained throughout it’s period of service.  This is ensured by periodic surveys carried out by the Authorities.  In general terms, the survey requirements require the vessel to be watertight below the freeboard deck and weathertight above the freeboard deck.  This means that the shell plating must be intact and the closures to all openings leading to the hull should be in efficient working order.  No alterations should be done to any structure that would adversely affect the watertight integrity of the hull without the approval of the appropriate survey authority.

It is essential that you are thoroughly familiar with the locations and closing mechanisms of all openings on your vessel through which water may enter the hull.  This way you will not neglect to maintain, test and check the efficiency of any of the closing arrangements.

Maintenance Items

Check that all access openings at ends of enclosed structures are in good condition.  All door clips, clamps, and hinges should be free and well greased.  All gaskets and watertight seals should be crack free.  Ensure that the doors open from both sides. Figure 1.25 shows the typical components of a weathertight door.

Weathertight door on Main deck

Check all cargo hatches and access to holds for weathertightness.

Seals should never be painted.

Regularly inspect all machinery space openings on exposed decks.


Check that any manholes and flush scuttles are capable of being made water-tight.

Check that all ventilator openings are provided with efficient weathertight closing appliances and repair any defects.

All airpipes of diameter exceeding 30mm bore, must be provided with permanently attached satisfactory means for closing the openings.

Ensure that the non-return valves on overboard discharges are operating in a satisfactory manner.

Check that all freeing ports are in a satisfactory condition, e.g. shutters are not jammed, hinges are free and that pins are of noncorroding material.  Check that any securing appliances, if fitted, work correctly.


You can test the efficiency of closures by means of a simple “hose test” or by a “chalk test”.