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What is a deck officer?

Marine Transportation Operations, Vessel Operations & Technology and Small Vessel Operations students study the safe navigation of a vessel and management of the deck department and are training to become deck officers or mates. Deck officers or "mates" perform the work for captains on vessels when they are on watch, like determining the course and speed, maneuver to avoid hazards, and continuously monitor the vessels position using charts and navigational aids. They also maintain logs and other records tracking the ships movements. They ensure that the proper procedures and safety practices are followed, check that machinery and equipment are in good working order, and oversee the loading and discharging of cargo or passengers. Mates supervise crew members engaged in maintenance and the primary upkeep of the vessel.

All mates "stand" watch for specified periods, usually a 4 hours on/8 hours off rotation. When more than one mate is necessary aboard a ship, they typically are designated 3rd Mate, 2nd mate, and Chief Mate. However, on smaller vessels, there may be only one mate who alternates watches with the captain.

Under the direction of the Mates, Able Seamen (AB's)perform duties such as standing watch for navigation, security, or communications, operate hoists, cranes, and winches to load cargo or set gangways; operate and maintain on-deck equipment and ship rigging, and handle lines to secure vessels to piers or other vessels.

Mates and ABs work primarily aboard commercial (merchant marine) or Military Sealift ships, in water transportation services (tugs, research vessels, offshore supply vessels and other water craft) and on passenger vessels (cruise ships, ferries, dinner/casino boats, traditional sail vessels, sightseeing/charter boats). Work schedules vary, depending on vessel type, but separation could be up to 90 days or more . Employment outlook is favorable with competitive starting salaries.


Before permitted to work aboard a commercial vessel, mariners must complete a rigorous licensing process. The U.S. Coast Guard promulgates the requirements for documentation and issuance of merchant mariner licenses for Deck and Engineer officers. USCG Deck officer licenses are issued by:

  • grade (e.g., 3rd Mate*, 2nd Mate, Chief Mate, Master (Captain), Mate* and Operator),
  • vessel tonnage (from not more than 5 ton to 50t, 100t, 200t*, 500t*, 1600t*, or unlimited tonnage*),
  • means of propulsion (i.e., Steam*, Motor*, Sail or Auxiliary Sail*),
  • route (e.g., Inland, Great Lakes, Near Coastal* or Oceans*),
  • and any vessel type restrictions.

License advancement is based on documented sea time, professional recertifications, and/or U.S.C.G. exams.


Standards of Training, Certification and Watchkeeping (STCW)* - STCW for seafarers set international standards for masters, officers and watch personnel on seagoing merchant ships. STCW training is intended to ensure that seafarers are aware of the hazards of working on a vessel and can respond appropriately in an emergency.

A STCW Certificate will be issued to mariners who meet the STCW requirements and is separate from U.S. Merchant Mariner license. STCW requires seafarers be provided with "familiarization training" and "basic safety training" which includes: basic fire fighting, elementary first aid, personal survival techniques, and personal safety and social responsibility. Mariners entering training programs after August 1, 1998, MMA license program students included, are required to meet the current international competency standards.

Automatic Radar Plotting Aids (ARPA)* and Global Maritime Distress Safety System (GMDSS)* for deck officers serving on vessels equipped with those systems.

* - available at MMA

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