Key difference: The deck officer or mate is essentially an officer serving in the deck department. Depending on the size of the ship, the deck department may have one or more deck officers. A deck cadet, on the other hand is an officer under training.

In order to maintain order and a line of authority, armed forces have different ranks. Armies and navies have professions and ranks, in which each rank had its designated authority and responsibility. This is not only true for military navies but for merchant navies, as well.

A merchant navy is a fleet of vessels that provide commercial services. Similar to a military vessel, a merchant vessel has distributed ranks and responsibilities. A merchant ship is essentially any ship that transports cargo and/or passengers.

The ship’s crew is headed by the Captain of the ship. The Captain acts in lieu of the owner and in the interest of the owner. The Captain is the Master when the ship is in transit. The crew itself is divided into four main categories: the deck department, the engineering department, the steward's department, and other.

The deck department is an organizational unit aboard naval and merchant ships. The deck department is then further divided into roles:

• Chief officer/chief mate
• Second officer/second mate
• Third officer/third mate
• Deck Cadet
• Boatswain
• Able seaman
• Ordinary seaman

The deck officer or mate is essentially an officer serving in the deck department. Depending on the size of the ship, the deck department may have one deck officer, or a chief officer and a second officer, or a chief officer, a second officer and a third officer. These officers are known as the deck officers. The chief officer heads the deck department and reports directly to the captain.

Some of the job descriptions of a chief officer are: administrative tasks such as scheduling work, quality control, coordinating with other departments, conflict resolution, compiling supply, overtime, and cost control records, and requisitions or purchases stores and equipment. In addition to these executive duties, he may or may be required to stand watch.

The second officer and the third officer are generally a watch officer. They keep watches and are responsible for the unlicensed crewmen on each of their respective watch. The deck officers in general are also responsible for navigation, maintenance of sea safety equipment, the supervision and management of staff, planning, organization and supervision of cargo loading and unloading, the supervision of mooring and unmooring, liaising between a ship’s Captain and crew, as well as updating charts and the ship’s log.

Deck officers are licensed officers, which means that they have generally passed an examination and are accredited. The also have expertise and experience.

A Deck Cadet, on the other hand, is the third rung from the bottom. They are the officers under training and are supposed to learn and know first aid and survival techniques, as well as firefighting. Deck Cadets are also trained in navigation, ship-handling, cargo-handling and maritime law. Despite the training, the main responsibility of a deck cadet is to observe and learn, in addition to helping out wherever possible; all under the command of the Chief Officer. At the end of their training, they will be considered competent and will receive a Certificate of Competency, hence becoming a full-fledged officer.

Image Courtesy: public.navy.mil, myship.com