33 CFR 20.1201 - Application.
(b) The Coast Guard may, for 45 days or less, suspend and seize a merchant mariner credential, license, certificate, or document if, when acting under the authority of the license, certificate, or document, -
(1) A mariner performs a safety-sensitive function on a vessel; and
(2) There is probable cause to believe that he or she -
(i) Has performed the safety-sensitive function in violation of law or Federal regulation regarding use of alcohol or a dangerous drug;
(ii) Has been convicted of an offense that would prevent the issuance or renewal of the merchant mariner credential, license, certificate, or document; or,
(iii) Three years or less before the start of an S&R proceeding, has been convicted of an offense described in subparagraph 205(a)(3)(A) or (B) of the National Driver Register Act of 1982 (23 U.S.C. 401, note).