A fraudulent breach of duty or willful act of known
   illegality on the part of a master of a ship, in his character of
   master, or of the mariners, to the injury of the owner of the ship or
   cargo, and without his consent. It includes every breach of trust
   committed with dishonest purpose, as by running away with the ship,
   sinking or deserting her, etc., or by embezzling the cargo.