46 U.S.C. § 7306: General requirements and classifications for members of deck departments

Able Seaman-Unlimited. Able Seaman-Limited. Able Seaman-Special. Able Seaman-Offshore Supply Vessels. Able Seaman-Sail. Able Seaman-Fishing Industry. Ordinary Seaman. the tonnage and means of propulsion of vessels; the waters on which vessels are to be operated; or other appropriate standards. is at least 18 years of age; has the service required by the applicable section of this part; is qualified professionally as demonstrated by an applicable examination or educational requirements; is qualified as to sight, hearing, and physical condition to perform the seafarer’s duties; and has satisfied any additional requirements established by the Secretary, including career patterns and service appropriate to the particular service, industry, or job functions the individual is engaged. under sections 7307 and 7309 of that title; or if the service is on board a vessel of at least 100 gross tons, under section 7308 of that title.”