A sea captain, ship's captain, captain, master, or shipmaster, is a high-grade licensed mariner who holds ultimate command and responsibility of a merchant vessel. The captain is responsible for the safe and efficient operation of the ship, including its seaworthiness, safety and security, cargo operations, navigation, crew management, and legal compliance, and for the persons and cargo on board.
The captain ensures that the ship complies with local and international laws and complies also with company and flag state policies. The captain is ultimately responsible, under the law, for aspects of operation such as the safe navigation of the ship, its cleanliness and seaworthiness, safe handling of all cargo, management of all personnel, inventory of ship's cash and stores, and maintaining the ship's certificates and documentation.
One of a shipmaster's particularly important duties is to ensure compliance with the vessel's security plan, as required by the International Maritime Organization's ISPS Code
