U.S. Coast Guard Requirements for Able Seaman Rating

Able Seaman (AB) is a deck rating that requires qualifying experience, exams, and approved training. A mariner that holds an AB endorsement is below Officer and above Ordinary Seaman. The level of AB you qualify for depends on your sea service experience: the amount of days you have documented, the size of the vessels, and the waters operated on.

National Able Seaman is a national (U.S. WATERS) rating. If you plan to use your AB credential in INTERNATIONAL waters, there are additional endorsements you will need and requirements to meet.

Prerequisites must be reviewed before applying for any U.S. Coast Guard credential. This is advised so you don't spend your time and money pursuing a license that you don't qualify for. For full consulting and credential services, click here to get more info. For credential packets and USCG forms click here.

But please, don't rule yourself out on your own. If you have any questions at all about whether you qualify for a credential, call us at (866)-300-5984 and one of our friendly Student Services advisors will answer your questions.

Prerequisites for National Able Seaman

You must meet all of the requirements established by the USCG National Maritime Center in order to apply for this endorsement. The USCG checklist of requirements is located here on the National Maritime Center website: https://www.dco.uscg.mil/nmc/checklist/. Under Deck Ratings click on National Able Seaman.

Important sea service requirements:

  • AB Unlimited requires 1080 days of deck service on Oceans or Great Lakes.
  • AB Limited requires 540 days of deck service on vessels of 100 Gross Tons or more, not exclusive to rivers & smaller inland lakes of the U.S.
  • AB Special requires 360 days of deck service on navigable waters of the U.S.
  • AB OSV (Offshore Supply Vessel) requires 180 days of deck service on navigable waters of the U.S.
  • AB Sail requires 180 days of deck service on sailing school vessels, oceanographic research vessels powered primarily by sail or equivalent sail vessels, on any navigable waters of the U.S.
  • AB Fishing requires 180 days of deck service, not as a processor, on any navigable waters of the U.S.

Lifeboatman qualification is required for all Able Seaman ratings. To obtain the Lifeboatman endorsement you must complete a USCG Approved course. See our Proficiency in Survival Craft/Lifeboatman course.

In order to use an Able Seaman rating on INTERNATIONAL WATERS, the following additional trainings are required under the International Standards of Training, Certification, and Watchkeeping Code (STCW) for seagoing vessels:

Basic Training is an STCW endorsement required for Able Seaman ratings. See our Basic Training course.

RFPNW (Rating Forming Part of a Navigational Watch) is an STCW endorsement required for Able Seamen on international waters. To get RFPNW endorsement you must meet the sea service, training, and assessment requirements for it. The USCG checklist of requirements is located here on the National Maritime Center website: https://www.dco.uscg.mil/nmc/checklist/. Under Deck Ratings click on STCW-RFPNW. Also see our RFPNW course.

Able Seafarer-Deck is an STCW endorsement that also requires sea service and training. It requires sea service that must have been accrued after you meet the RFPNW qualifications. See checklist for Deck Ratings and click on STCW Able Seafarer-Deck.

For full information on credential requirements, refer to the USCG National Maritime Center website.