Maritime Security Levels
(MARSEC Levels)

The Coast Guard employs a three-tiered system of Maritime Security (MARSEC) Levels designed to easily communicate to the Coast Guard and its maritime industry partners pre-planned scalable responses for credible threats. If the Secretary of Homeland Security issues an NTAS Alert, the Commandant of the U.S. Coast Guard will adjust the MARSEC Level, if appropriate.

MARSEC Levels are set to reflect the prevailing threat environment to the marine elements of the national transportation system, including ports, vessels, facilities, and critical assets and infrastructure located on or adjacent to waters subject to the jurisdiction of the U.S.  MARSEC Levels apply to vessels, Coast Guard-regulated facilities inside the U.S., and to the Coast Guard.

National Terrorism Advisory System:  The alerts under the new system replacing the five color DHS system will indicate if there is an “imminent threat” or an “elevated threat”.

MARSEC Level 1 – minimum appropriate security measures in place at all times.  Normalcy under NTAS

MARSEC Level 2 – additional measures to Level 1 for heightened risk.  Elevated under NTAS

MARSEC Level 3 – further specific protective measures above Levels 1 & 2 for a probable or imminent threat.  Imminent under NTAS.