33 CFR 6.04-5: -5 Preventing access of persons, articles, or things, including any data, information, network, program, system, or other digital infrastructure, to vessels, or waterfront facilities.

The Captain of the Port may prevent any person, article, or thing, including any data, information, network, program, system, or other digital infrastructure, from boarding or being taken or placed on board any vessel or entering or being taken into or upon or placed in or upon any waterfront facility whenever it appears to the Captain of the Port that such action is necessary in order to secure such vessel from damage or injury or to prevent damage or injury to any vessel, or waterfront facility, including any data, information, network, program, system, or other digital infrastructure therein or thereon, or waters of the United States, or to secure the observances of rights and obligations of the United States.