A typical deck department for a merchant ship would include:
Depending on the size and employment of the ship, a boatswain may be employed. If carried, the boatswain, generally a senior able seaman will act as a foreman of the ship's deck crew and as the chief mate's representative on deck.
The chief mate is the head of the deck department. This involves administrative tasks such as scheduling work, quality control, coordinating with other departments, and conflict resolution. The chief mate also compiles supply, overtime, and cost control records, and requisitions or purchases stores and equipment.
Due to IMO regulations, larger cargo and passenger ships generally carry at least three able seamen and may carry ordinary seamen.
The ship's other deck officers, generally a Second Mate and Third Mate are also members of the deck department.
Examples include maintenance and upkeep of the ship, handling of the ship's rigging and ground tackle, coordination of underway replenishment operations, conductance of minesweeping operations, maintenance and operation of the ship's boats, supervision of diving and salvage operations (including towing), and serving as shipboard seamanship specialists. Undesignated seamen, or those who have not selected a rating (e.g. job or vocation), are normally the most junior sailors onboard and are usually sent to the Deck Department for their first assignment.
Deck Department professionals are led by Boatswain's Mates, sailors who have chosen seamanship as their primary area of expertise. Depending on ship type and size, the Deck Department can be a division or ship's department. On some ships the First Lieutenant serves as the Deck Department's division officer and is a junior officer (usually an Ensign or Lieutenant Junior Grade) while the Operations Officer serves as the department head. On others the Deck department is its own department, reporting directly to the ship's Commanding Officer.