Article 27 of Mexico’s Law of Navigation and Maritime Commerce says: “El capitán de la embarcación será a bordo la primera autoridad” (The captain of the vessel shall be the first authority on board).
The captain is responsible for the vessel, its crew, passengers and cargo, “y de los actos jurídicos que realice, aún cuando no se encuentre a bordo” (and for the legal acts he performs, even when he is not on board).