33 CFR 95.040 : Navigation And Navigable Waters (§ 1.01-1 To Parts 404-499) — (§ 1.01-1 To Parts 121-124) — Coast Guard, Department Of Homeland Security (§ 1.01-1 To Parts 121-124) — Vessel Operating Regulations (§ 95.001 To Subpart B) — Operating A Vessel While Under The Influence Of Alcohol Or A Dangerous Drug (§ 95.001 To § 95.050) — Refusal to submit to testing.

(a) If an individual refuses to submit to or cooperate in the administration of a timely chemical test when directed by a law enforcement officer based on reasonable cause, evidence of the refusal is admissible in evidence in any administrative proceeding and the individual will be presumed to be under the influence of alcohol or a dangerous drug.

(b) If an individual refuses to submit to or cooperate in the administration of a timely chemical test when directed by the marine employer based on reasonable cause, evidence of the refusal is admissible in evidence in any administrative proceeding.