The USCG is America's only armed service with responsibility & authority for direct law enforcement action, on land police officers must meet 'reasonable suspicion' requirement.
The Coast Guard is firmly committed to continuing the 'drug war' in the maritime area and, accordingly, drug interdiction is the most significant Coast Guard mission in terms of effort dedicated and money spent. A broad grant of enforcement authority from Congress coupled with an equally broad deference by the judiciary to the use of that power has facilitated this commitment.
Congress provided its principal support of Coast Guard law enforcement almost half a century ago, with a statute that has not required amendment to meet modern exigencies. The courts, however, have fully endorsed unfettered authority for the agency's law enforcement mission only during the last two decades as a perceived need for this wide latitude arose in the context of halting the flood of illegal drugs from South America.
Vessel owners must accept as part of the 'cost' of enjoying waterborne business or recreation the possibility that the Coast Guard may stop and board their vessel at any time. For the recreational boater who already faces pervasive regulations that require him to carry certain expensive equipment in order to enjoy his leisure time aboard a vessel which itself requires a substantial investment, the appearance of a Coast Guard law enforcement team is particularly disturbing.
Nevertheless Coast Guard officers have broad authority for stopping vessels subject to United States jurisdiction, and owners and operators have no legal grounds for complaint against being stopped and searched.