3. Restriction on Authority.—
The master is the owner's agent in all matters fairly within the scope of his authority but has no more authority to bind him than any other special agent. He is not a general agent and his powers are usually confined to the property in his charge. In cases of necessity, when the owner is not present, his authority is very broad but it is correspondingly restricted when the owner is present. He cannot bind the owner personally beyond the value of the ship and freight pending; he cannot vary or annul the owner's agreements; he cannot make a promissory note binding on the owner; or bind him for cargo not actually on board by a bill-of-lading;[8] or admit an invalid claim; nor purchase a cargo on his account.
In dealing with other persons on board his vessel his authority is as broad as the exigencies of his situation require and he may, in proper cases, and after exhausting pacific measures put even passengers under arrest. But he cannot delegate this authority to minor officials or others on board but must personally exercise such responsible duties and see to it that nothing unreasonable is done. It has been held that while he may restrain, or even confine, a passenger who refuses to submit to the necessary discipline of the ship, he ought not to inflict any higher punishment than a reprimand upon a passenger without first conferring with his officers and entering the facts on the log. His authority to punish members of the crew must be exercised with moderation and in reason. He has no authority to punish by flogging or the use of any illegal instrument and in testing the legality of punishment or chastisement the methods and weapons employed are important.[9]