(a) MARSEC Levels advise the maritime community and the public of the level of risk to the maritime elements of the national transportation system. Ports, under direction of the local COTP, will respond to changes in the MARSEC Level by implementing the measures specified in the AMS Plan. Similarly, vessels and facilities required to have security plans under part 104, 105, or 106 of this subchapter shall implement the measures specified in their security plans for the applicable MARSEC Level.

(b) Unless otherwise directed, each port, vessel, and facility shall operate at MARSEC Level 1.

(c) The Commandant will set (raise or lower) the MARSEC Level commensurate with risk, and in consideration of any maritime nexus to any active National Terrorism Advisory System (NTAS) alerts. Notwithstanding the NTAS, the Commandant retains discretion to adjust the MARSEC Level when necessary to address any particular security concerns or circumstances related to the maritime elements of the national transportation system.

(d) The COTP may raise the MARSEC Level for the port, a specific marine operation within the port, or a specific industry within the port, when necessary to address an exigent circumstance immediately affecting the security of the maritime elements of the transportation in his/her area of responsibility. Application of this delegated authority will be pursuant to policies and procedures specified by the Commandant.