A more thorough explanation:

A seaworthy vessel is a ship, brig, sloop, or any other craft that is capable of navigating on water. To be considered a vessel under the Jones Act, the structure's purpose must be to transport passengers, cargo, or equipment from place to place across navigable waters.

For example, a cargo ship that transports goods from one port to another is a seaworthy vessel. A fishing boat that is not used to carry passengers for hire is not considered a seaworthy vessel.

A vessel is considered seaworthy if it can withstand the ordinary stress of the wind, waves, and other weather that seagoing vessels might ordinarily be expected to encounter. In some legal contexts, the question of whether a vessel is seaworthy includes whether it is fit to carry an intended cargo properly.

For instance, if a cargo ship is carrying perishable goods, it must be seaworthy enough to ensure that the goods reach their destination without spoiling. If the ship is not seaworthy and the goods are damaged, the shipowner may be held liable for the damages.