MARSEC Level 1 is the baseline maritime security posture that every U.S. port, vessel, and regulated facility maintains at all times, unless the Coast Guard directs otherwise. It sets the minimum protective measures that must be in place even when no specific threat has been identified, and it comes from federal regulations at 33 CFR Part 101, which implement the Maritime Transportation Security Act of 2002. In practical terms, if you work in or around the maritime industry, Level 1 is what you operate under nearly all of the time.
Where Level 1 Sits Among the Three MARSEC Levels
Federal regulations recognize three MARSEC Levels, each tied to the current risk of a transportation security incident. Level 1 is the minimum baseline maintained at all times. Level 2 applies for a sustained period when risk is heightened. Level 3 is the most restrictive, imposed for a limited time when a security incident is probable or imminent, even if the specific target is unknown.1eCFR. 33 CFR 101.105 – Definitions
The Coast Guard Commandant sets the level nationally, weighing current risk and any active National Terrorism Advisory System alerts. A local Captain of the Port can also raise the level for a specific port, marine operation, or industry within their area when an urgent situation demands it.2eCFR. 33 CFR 101.200 – MARSEC Levels Changes are communicated through Broadcast Notices to Mariners and electronic means.
What Level 1 Requires Day to Day
Every covered vessel and facility must have a Coast Guard-approved security plan that spells out specific measures for each MARSEC Level.3GovInfo. 46 USC 70103 – Maritime Transportation Security Plans The regulations don’t hand down a single checklist. Instead, they require each plan to address certain categories of protective measures, tailored to the specific vessel or facility.
Access Control
Controlling who boards is the backbone of Level 1. Vessels must identify access points to be secured or attended, lock spaces adjoining passenger or visitor areas when unattended, and screen people and baggage for dangerous items at rates specified in their approved plan.4eCFR. 33 CFR 104.265 – Security Measures for Access Control Anyone who cannot or will not establish their identity can be denied boarding, and the incident must be reported.
Facilities follow a parallel set of rules. Signs must be conspicuously posted explaining that entering the facility constitutes consent to screening and that refusing screening means being turned away. Restricted areas within the facility must be designated and their access controlled.5eCFR. 33 CFR 105.255 – Security Measures for Access Control
Monitoring and Patrols
Security personnel or watchkeepers monitor the vessel and its surroundings, including waterside approaches. Surveillance equipment and intrusion-detection devices supplement human patrols, and lighting must be sufficient during darkness to identify people attempting to access the vessel or facility.6eCFR. 33 CFR Part 104 – Maritime Security: Vessels All security equipment must be kept operational and regularly maintained.
Cargo and Stores
Procedures for cargo and ship’s stores aim to prevent tampering or the introduction of unauthorized materials. At Level 1, these checks are routine rather than exhaustive, but they still require verifying that cargo matches its documentation and that supplies delivered to the vessel are expected and accounted for.6eCFR. 33 CFR Part 104 – Maritime Security: Vessels
TWIC at Level 1
The Transportation Worker Identification Credential is the federal ID that controls access to secure areas of ports and vessels. At Level 1, no one may enter a secure area of a facility unescorted without a valid TWIC. Facilities classified as Risk Group A must verify the credential electronically; other facilities can use either electronic or visual inspection.5eCFR. 33 CFR 105.255 – Security Measures for Access Control Vessels have equivalent requirements consistent with their assigned risk group.4eCFR. 33 CFR 104.265 – Security Measures for Access Control
People without a TWIC, such as visitors, vendors, or passengers, can still enter, but their identification must be checked and they must provide a documented reason for being there, such as a work order, boarding pass, or government ID.
When a Declaration of Security Is Required at Level 1
Even at the baseline level, certain vessel-facility interactions require a formal written agreement called a Declaration of Security. A facility receiving a cruise ship, or a manned vessel carrying certain dangerous cargo in bulk, must coordinate security procedures with the vessel before it arrives. The Facility Security Officer and the vessel’s Master or Vessel Security Officer agree on the contents and sign the declaration upon arrival. No passengers may embark or disembark, and no cargo or stores may transfer, until the declaration is signed and in effect.7eCFR. 33 CFR 105.245 – Declaration of Security (DoS)
Who Is Accountable
Three designated officer positions carry the weight of Level 1 compliance.
The Vessel Security Officer is designated for every covered vessel. On manned vessels, the VSO must be the Master or a crew member. The VSO regularly inspects the vessel, oversees the security plan, coordinates cargo and supply handling, ensures equipment works, and reports problems to the Company Security Officer. The VSO must hold a valid TWIC and remains personally responsible for any duties delegated to other crew.8eCFR. 33 CFR 104.215 – Vessel Security Officer (VSO)
The Facility Security Officer ensures the facility security assessment is conducted, the plan is developed and implemented, and annual audits are performed. The FSO also coordinates with vessels, executes Declarations of Security, and briefs personnel on changes in security conditions. The FSO must maintain a TWIC.9eCFR. 33 CFR 105.205 – Facility Security Officer (FSO)
The Company Security Officer sits above the VSO in the organizational chain, supports vessel-level officers, ensures vessels stay informed of potential threats, and receives reports on problems identified during audits or inspections. Proposed changes to a vessel security plan flow up through the CSO.
Training and Recordkeeping
Security training is not limited to the designated officers. All vessel personnel, including part-time workers and contractors, must understand the relevant parts of the vessel security plan, what each MARSEC Level means and requires of them, how to recognize dangerous items and suspicious behavior, and how the TWIC program works.10eCFR. 33 CFR 104.225 – Security Training for All Other Vessel Personnel Facility personnel have equivalent obligations under their own plans.
The Vessel Security Officer must keep records of all training and drills for at least two years and make them available to the Coast Guard on request.11eCFR. 33 CFR 104.235 – Vessel Recordkeeping Requirements Inspectors check training records early, so letting them lapse is a reliable way to draw enforcement attention.
Penalties for Falling Short
Failing to comply with maritime security regulations, including the measures required at Level 1, carries real consequences. A person who violates the requirements of 33 CFR Subchapter H, including Maritime Security Directives, faces a civil penalty of up to $25,000 per violation.12eCFR. 33 CFR 101.415 – Penalties More serious violations of Coast Guard security orders can trigger additional civil and criminal penalties under 46 U.S.C. 70036 or 70052. The Coast Guard conducts regular compliance inspections, and deficiencies found during those inspections can lead to enforcement action, operational restrictions, or both.