The Captain or Master is in command of the ship He is responsible for the vessels navigation, discipline, safety of passengers, crew and the cargo. It is the job of the Captain to set the course for the ship and the speed too. They are in charge of maneuvering the ship to avoid hazards and locate the ship's position using navigational aids.
The captain or master is the sole representative of the ship's owner. He is in charge for assigning organizational duties for ship's operation, navigation and maintenance with the chief mate. The chief mate, also known as first mate or chief officer acts as the master's first assistant. He is in charge of all cargo planning and deck work. He assists with navigation and discipline and helps to maintain order. He is in charge of the training of company cadets.
The second mate is in charge of mails, the maintenance of all equipment and charts used for navigation. He is responsible for helping the captain in planning & executing the sailing schedule. He is also the medical officer for upkeep of general health of the crew & staff and is trained in first aid. The third mate is responsible for maintenance of lifeboats and firefighting equipment. He acts as signal officer in charge of all signaling equipment and assists with cargo work. One mate usually stands watch as in charge of the navigating bridge. In ports the third officer alternates port watches with second officer. In port duties he keeps cargo watch to ensure smooth loading & off loading and observing the cargo loading plan, port and company regulations