SQA Chief Mate Stability Theory Practice Test 2026 - Complete Exam Prep

Icing significantly impacts the stability of a vessel by increasing the vertical center of gravity (KG) when ice accumulates on deck. This increase in KG leads to a higher center of gravity, which affects the vessel's ability to return to an upright position after being tilted by external forces such as wind or waves. When the KG rises, the metacentric height (GM) decreases, resulting in reduced residual stability, making the vessel more prone to capsizing.

In practical terms, as ice builds up, it adds weight and shifts the center of that weight higher on the vessel. This change compromises the ship's stability characteristics, which can be critical in adverse weather conditions. The alteration in stability parameters means that the vessel may not be able to withstand the same level of heel before reaching a point of no return. Therefore, the correct understanding of how icing affects a vessel’s stability is crucial for maintaining safety at sea.