33 USC 1226 - Port, harbor, and coastal facility security

(a) General authority 
The Secretary may take actions described in subsection (b) of this section to prevent or respond to an act of terrorism against
(1) an individual, vessel, or public or commercial structure, that is
(A) subject to the jurisdiction of the United States; and
(B) located within or adjacent to the marine environment; or

view counter
(2) a vessel of the United States or an individual on board that vessel.
(b) Specific authority 
Under subsection (a) of this section, the Secretary may
(1) carry out or require measures, including inspections, port and harbor patrols, the establishment of security and safety zones, and the development of contingency plans and procedures, to prevent or respond to acts of terrorism;
(2) recruit members of the Regular Coast Guard and the Coast Guard Reserve and train members of the Regular Coast Guard and the Coast Guard Reserve in the techniques of preventing and responding to acts of terrorism; and
(3) dispatch properly trained and qualified armed Coast Guard personnel on vessels and public or commercial structures on or adjacent to waters subject to United States jurisdiction to deter or respond to acts of terrorism or transportation security incidents, as defined in section 70101 of title 46.
(c) Nondisclosure of port security plans 
Notwithstanding any other provision of law, information related to security plans, procedures, or programs for passenger vessels or passenger terminals authorized under this chapter is not required to be disclosed to the public.