Your examiner asks: "What is the purpose of an inclining experiment, when is it carried out, and what does it determine?" Give a complete answer.

A. The inclining experiment determines the maximum cargo capacity of a vessel. It is carried out by the class society surveyor at each annual survey.

B. The inclining experiment determines the position of the ship's centre of gravity (KG) in the lightship condition by deliberately heeling the vessel using known masses moved known distances and measuring the resulting heel angle. From this, KM (from hydrostatic tables) and the measured GM allow KG to be calculated. It is carried out: on new builds; after major structural alterations; when the KG is in doubt (e.g., major refit). The results inform the Stability Booklet calculations for all loading conditions.

C. The inclining experiment tests the vessel's behaviour in beam seas. It involves deliberately rolling the vessel using ballast pumps to determine the period of roll.

D. The inclining experiment is only carried out on passenger vessels. Cargo vessels determine KG from the loading computer without a physical inclining experiment.

A. GM is the distance between the keel and the metacentre. A higher GM always means a safer, more stable vessel regardless of its magnitude.

B. GM is always a positive value. A negative GM means the ship is overloaded and must discharge cargo immediately.

C. GM (metacentric height) is the distance between the centre of gravity (G) and the metacentre (M). A positive GM (M above G) indicates stable equilibrium — the vessel will right itself when heeled. A very low GM risks loll, slow period of roll, and potential capsize. A very high GM (stiff ship) causes a rapid, violent rolling motion that can create excessive dynamic loads on cargo, structures, and crew — which can be as dangerous as low stability.

D. GM only applies to loaded conditions. In ballast, stability is assessed using only the KG value.

A. The IMO IS Code applies to new vessels only. Older vessels built before 2010 comply with the 1966 Load Lines convention stability requirements only.

B. The minimum GM under all criteria is 0.5 metres. The GZ curve must reach a maximum of at least 0.5m at any angle between 20 and 60 degrees.

C. The only IMO requirement is that the angle of vanishing stability must exceed 60 degrees. Area under the curve and initial GM are national flag state requirements only.

D. Key GZ curve features: range of stability (angle at which GZ returns to zero); maximum GZ and angle of maximum GZ; area under the curve (dynamical stability). IMO IS Code 2008 criteria: area 0-30 degrees minimum 0.055 metre-radians; area 0-40 degrees (or to flooding angle if less than 40) minimum 0.090 metre-radians; area 30-40 degrees minimum 0.030 metre-radians; maximum GZ at least 0.200 metres at 30 degrees or greater; initial GM not less than 0.150 metres.