Section 12.401 - General requirements for able seaman (A/B) endorsements(a)General. An A/B is any person below officer and above ordinary seaman who holds a merchant mariner credential (MMC) or merchant mariner document (MMD) endorsed as A/B by the Coast Guard.(b)Categories. The following categories of able seaman endorsements are established:(1) Able seaman-unlimited.(4) Able seaman-offshore supply vessels.(6) Able seaman-fishing industry.(c)Requirements for certification. To qualify for an endorsement as able seaman, an applicant must-(1) Be at least 18 years of age;(2) Pass the prescribed physical and medical examination requirements specified in 46 CFR, part 10, subpart C;(3) Present evidence of having passed a chemical test for dangerous drugs or of qualifying for an exemption from testing as described in § 16.220 of this subchapter;(4) Meet the sea service or training requirements set forth in this part;(5) Pass an examination for able seaman;(6) Qualify for an endorsement as lifeboatman or lifeboatman-limited; and(7) Speak and understand the English language as would be required in performing the general duties of able seaman and during an emergency aboard ship.(d)Additional requirements.(1) The holder of an MMC or MMD endorsed for the rating of A/B may serve in any rating in the deck department without obtaining an additional endorsement, provided-(i) That the holder possesses the appropriate A/B endorsement for the service of the vessel; and(ii) That the holder possesses the appropriate STCW endorsement when serving as an able seafarer-deck or Ratings forming part of the navigational watch on a seagoing ship.(2) After March 24, 2014, any MMC endorsed as A/B will also be endorsed as lifeboatman or lifeboatman-limited, as appropriate.(3) The A/B endorsement will clearly describe the type of rating that it represents (see paragraph (a) of this section).