Roll

Roll is the side-to-side rotation of a vessel around its longitudinal axis, causing the port and starboard sides to rise and fall. It is most noticeable in beam seas, quartering waves, or when swell meets the hull at an unfavourable angle. Every hull has a natural roll period, influenced by beam, displacement, ballast, loading, and stabilisation systems.

Excessive roll reduces comfort, increases fatigue and seasickness, and can make deck work, cooking, watchkeeping, and steering less safe. It may also shift gear or cargo and reduce performance under sail or power. When planning a passage, assess Sea State, Wave Height, and Wave Period to avoid conditions likely to produce heavy rolling.

Skippers manage roll by altering course or speed, reefing, balancing sail plan, securing loose items, or using fins, gyros, trim tabs, or other stabilisers. PredictWind wave forecasts and Weather Routing help compare routes and departure times to minimise uncomfortable beam-on swell offshore.