Safety

Able to prevent water entering under the environmental conditions likely to be encountered, without necessarily resisting continuous immersion. Weathertight doors, hatches and covers protect spaces from rain, spray and boarding seas when properly closed and maintained. The term is distinct from watertight, which denotes resistance to water pressure from either or a specified side.

A lifeboat or liferaft intended to sustain people after they abandon a vessel. It provides buoyancy, protection and survival equipment appropriate to its approval and service. Stowage, launching arrangements, capacity, maintenance and crew familiarisation are governed by the vessel’s applicable safety requirements.

The watertight volume above a vessel’s loaded waterline that remains available to oppose further immersion. Adequate freeboard and intact closures preserve this margin as the vessel heels, ships water or carries additional load. Flooding, overloading and downflooding openings reduce reserve buoyancy and can rapidly compromise survivability.

The practical knowledge and abilities required to operate and care for a vessel safely. They include ropework, steering, lookout, anchoring, mooring, sail or machinery handling, weather awareness, maintenance and emergency response. Competence combines correct technique with judgement, communication and adaptation to the vessel and conditions.

The loss of stability caused when liquid moves across a partly filled compartment as a vessel heels. The shifting liquid moves the combined centre of gravity toward the low side and reduces effective metacentric height. Tanks should be kept pressed full or empty where practicable, and flooding or water on deck must be controlled promptly.

The condition in which a heeled vessel develops a righting moment that tends to return it upright. It exists while the centre of buoyancy and centre of gravity create a positive righting lever. The range and strength of positive stability depend on hull form, loading, free-surface effects and watertight integrity.

The date after which a marine pyrotechnic is no longer considered within its approved service life. Expired flares may be unreliable or unsafe and should not be kept as a substitute for in-date distress equipment. They require disposal through an authorised route and must never be tested, dismantled or placed in ordinary waste.