Seaworthiness is a concept that runs through maritime law in at least four contractual relationships. In a marine insurance voyage policy, the assured warrants that the vessel is seaworthy. A carrier of goods by sea owes a duty to a shipper of cargo that the vessel is seaworthy at the start of the voyage. A shipowner warrants to a charterer that the vessel under charter is seaworthy; and similarly, a shipbuilder warrants that the vessel under construction will be seaworthy.