36 CFR § 3.10 - What are the regulations regarding operating a vessel while under the influence of alcohol and/or drugs?
(a) Operating or being in actual physical control of a vessel is prohibited while:
(1) Under the influence of alcohol, a drug or drugs, or any combination thereof, to a degree that renders the operator incapable of safe operation; or
(2) The alcohol concentration in the operator's blood or breath is 0.08 grams or more of alcohol per 100 milliliters of blood or 0.08 grams or more of alcohol per 210 liters of breath.
(b) If State law that applies to operating a vessel while under the influence of alcohol establishes more restrictive limits of alcohol concentration in the operator's blood or breath, those limits apply rather than the limits specified in paragraph (a) of this section.
(c) The provisions of this section also apply to an operator who is or has been legally entitled to use alcohol or drugs.