The Coast Guard employs a three-tiered system of Maritime Security (MARSEC) Levels designed to easily communicate to the Coast Guard and our 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 MARSEC Level, if appropriate, based on the commensurate risk, any maritime nexus, and/or Commandant consultation with the Secretary of Homeland Security.
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.
MARSEC Level 1 generally applies in the absence of an NTAS Alert or when the Commandant determines that the Alert is not applicable to the Marine Transportation System. If an NTAS Alert is applicable, the Commandant will consider a MARSEC Level change for the maritime industry, Coast Guard, or both.
To add the current MARSEC Level to your web site, insert the following tag into your html source code.
<iframe src="//www.uscg.mil/safetylevels/" width="160" height="65" frameborder="0" scrolling="no"></iframe>