mer. law. The ability of a ship or other vessel to make a sea voyage with probable safety: there is, in every insurance, whether on ship or goods, an implied warranty that the ship shall be worthy when she sails on the voyage insured; that is, that she shall be tight, staunch, and strong, properly manned, provided with all necessary stores, and in all respects fit for the intended voyage. 2. The following rules have been established in regard, to the warranty of sea-worthiness.