46 CFR 12.403: Service and training for Able Seafarer endorsements
Last reviewed: October 14, 2026
This section sets the minimum service on deck needed for each category of Able Seafarer endorsement. It also allows approved training programs to be substituted for required service on deck. A school ship graduate may qualify without further service, and other programs may replace up to one-third of the required service.
Applies toApplicants seeking an endorsement as Able Seafarer in the categories listed in this section.
What it says
Able Seafarer-Unlimited requires three years of service on deck on vessels operating on oceans or on the Great Lakes.
46 CFR 12.403(a)(1)“Three years of service on deck on vessels operating on oceans or on the Great Lakes.”
Able Seafarer-Limited requires eighteen months of service on deck on vessels of 100 GRT or more which operate in a service not exclusively confined to the rivers and smaller inland lakes of the United States.
46 CFR 12.403(a)(2)“Eighteen months of service on deck on vessels of 100 GRT or more which operate in a service not exclusively confined to the rivers and smaller inland lakes of the United States.”
Able Seafarer-Special requires twelve months of service on deck on vessels operating on oceans or the navigable waters of the United States, including the Great Lakes.
46 CFR 12.403(a)(3)“Twelve months of service on deck on vessels operating on oceans or the navigable waters of the United States, including the Great Lakes.”
Able Seafarer-OSV requires six months of service on deck on vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.
46 CFR 12.403(a)(4)“Six months of service on deck on vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.”
Able Seafarer-Fishing Industry requires six months of service on deck, not as a processor, onboard vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.
46 CFR 12.403(a)(6)“Six months of service on deck, not as a processor, onboard vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.”
A graduate of a school ship may qualify for a rating endorsement as Able Seafarer, without further service, upon satisfactory completion of the program of instruction.
46 CFR 12.403(b)(1)“A graduate of a school ship may be qualified for a rating endorsement as Able Seafarer, without further service, upon satisfactory completion of the program of instruction.”
Training programs other than school ships may be substituted for up to one-third of the required service on deck.
46 CFR 12.403(b)(2)“Training programs, other than those classified as a school ship, may be substituted for up to one-third of the required service on deck.”
The Coast Guard will determine the service/training ratio for each program and may allow a maximum of 3 days of deck service credit for each day of instruction.
46 CFR 12.403(b)(2)“The Coast Guard will determine the service/training ratio for each program and may allow a maximum of 3 days of deck service credit for each day of instruction.”
Common questions
How much sea service do I need for Able Seafarer-Unlimited?
You need three years of service on deck on vessels operating on oceans or on the Great Lakes.
“Three years of service on deck on vessels operating on oceans or on the Great Lakes.”
Can training replace sea service for an Able Seafarer endorsement?
A school ship graduate may qualify without further service after satisfactorily completing the program of instruction. Other training programs may be substituted for up to one-third of the required service on deck.
“Training programs, other than those classified as a school ship, may be substituted for up to one-third of the required service on deck.”
How many days of deck service credit can I get per day of training?
The Coast Guard will determine the service/training ratio for each program. It may allow a maximum of 3 days of deck service credit for each day of instruction.
“The Coast Guard will determine the service/training ratio for each program and may allow a maximum of 3 days of deck service credit for each day of instruction.”
What is a school ship for Able Seafarer purposes?
A school ship is an institution that offers a complete approved program of instruction, including a period of at-sea training, in the skills appropriate to the rating of Able Seafarer.
““school ship” is interpreted to mean an institution that offers a complete approved program of instruction, including a period of at-sea training, in the skills appropriate to the rating of Able Seafarer.”
The text of 46 CFR 12.403
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Service or training requirements for Able Seafarer endorsements
(a) The minimum service required to qualify for the various categories of endorsement as Able Seafarer is as follows:
(1) Able Seafarer-Unlimited. Three years of service on deck on vessels operating on oceans or on the Great Lakes.
(2) Able Seafarer-Limited. Eighteen months of service on deck on vessels of 100 GRT or more which operate in a service not exclusively confined to the rivers and smaller inland lakes of the United States.
(3) Able Seafarer-Special. Twelve months of service on deck on vessels operating on oceans or the navigable waters of the United States, including the Great Lakes.
(4) Able Seafarer-OSV. Six months of service on deck on vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.
(5) Able Seafarer-Sail. Six months of service on deck on sailing school vessels, oceanographic research vessels powered primarily by sail, or equivalent sailing vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.
(6) Able Seafarer-Fishing Industry. Six months of service on deck, not as a processor, onboard vessels operating on oceans or on the navigable waters of the United States, including the Great Lakes.
(b) Approved training programs may be substituted for the required periods of service on deck as follows:
(1) A graduate of a school ship may be qualified for a rating endorsement as Able Seafarer, without further service, upon satisfactory completion of the program of instruction. For this purpose, “school ship” is interpreted to mean an institution that offers a complete approved program of instruction, including a period of at-sea training, in the skills appropriate to the rating of Able Seafarer.
(2) Training programs, other than those classified as a school ship, may be substituted for up to one-third of the required service on deck. The Coast Guard will determine the service/training ratio for each program and may allow a maximum of 3 days of deck service credit for each day of instruction.
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.