A ship must be fit for the voyage it is about to make. Seaworthiness is the condition of a vessel being properly designed, constructed, maintained, equipped, manned, and supplied so that it can encounter the ordinary perils of the sea for the intended voyage.

The concept is central to contracts of carriage and to marine insurance. Carriers have a duty to exercise due diligence to make the ship seaworthy before and at the beginning of the voyage. Unseaworthiness can defeat liability defenses and insurance cover.

Seaworthiness is relative to the voyage: a ship fit for coastal trade may not be fit for a winter North Atlantic crossing. Courts look at structure, equipment, competence of crew, and adequacy of stores. Maintaining seaworthiness is a continuous obligation of ownership and management.

• Fitness of a ship for its intended voyage
• Covers structure, equipment, manning, and supply
• Central to carriage contracts and insurance
• Assessed relative to the planned passage