List refers to a ship’s sustained, static tilt to one side — port or starboard — measured in degrees, and typically caused by uneven distribution of weight (cargo, ballast, or fuel) across the vessel’s width.
List vs Heel vs Trim
These three terms are often confused but describe distinct conditions:
- List — a static, sustained sideways tilt caused by an underlying weight imbalance; doesn’t correct itself until the cause is addressed
- Heel — a temporary sideways tilt caused by an external force (wind, turning, waves); corrects itself once the force is removed
- Trim — the fore-and-aft tilt (bow-down or stern-down), caused by uneven weight distribution along the ship’s length rather than across its width
Common Causes of List
- Uneven cargo loading (more weight on one side than the other)
- Uneven ballast or fuel tank filling
- Flooding affecting one side of the vessel more than the other (a serious, urgent stability concern)
- Cargo shift during the voyage
Why List Matters
A significant list reduces a vessel’s remaining stability reserve on the side it’s listing toward, and in serious cases (particularly flooding-related list) can be an early warning sign of a developing stability emergency requiring immediate corrective action.
Correcting List
Depending on the cause, list is corrected by adjusting ballast distribution, redistributing or re-securing cargo, or addressing the underlying issue (such as flooding) directly.
Exam Relevance
List calculations, causes, and correction methods are core Ship Stability topics in deck officer competency exams, often paired with trim calculations in combined problems.