This article provides general information, not legal, regulatory or financial advice. Requirements depend on the applicable contract, authority and jurisdiction.
Why the US regime has a different name
After 2001 the IMO produced the ISPS Code, and the United States passed the Maritime Transportation Security Act in 2002. The two were developed in parallel and are broadly aligned, but the US did not adopt ISPS as its domestic law. It wrote its own, in 33 CFR Parts 101 to 106.
The practical consequence is that in a US port you are inspected against the Code of Federal Regulations, not against the ISPS Code. Most of the substance matches. The vocabulary, the thresholds and the enforcement do not.
| ISPS (international) | MTSA (United States) | |
|---|---|---|
| Instrument | SOLAS Chapter XI-2 and the ISPS Code | 33 CFR Parts 101–106 |
| Threat levels | Security Levels 1, 2, 3 | MARSEC Levels 1, 2, 3 |
| Ship document | International Ship Security Certificate | ISSC accepted for foreign vessels; US vessels hold a Vessel Security Plan |
| Facility document | Port Facility Security Plan | Facility Security Plan under 33 CFR 105 |
| Enforcer | The Contracting Government | US Coast Guard, through the Captain of the Port |
| Personnel credential | National arrangements vary | TWIC — a specific biometric credential |
The parts, and which one applies to you
The regulation is split by what you are, and knowing which Part governs you is the first step in reading it.
| Part | Covers | Who reads it |
|---|---|---|
| 33 CFR 101 | General provisions, MARSEC levels, definitions | Everyone |
| 33 CFR 103 | Area Maritime Security, the committees and area plans | Port authorities, agents, planners |
| 33 CFR 104 | Vessels — security plans, officers, drills, records | Owners, managers, masters |
| 33 CFR 105 | Facilities — the shoreside terminal regime | Terminal operators, facility security officers |
| 33 CFR 106 | Outer Continental Shelf facilities | Offshore operators |
For a foreign-flag vessel calling a US port, the two that matter are 104 — which sets what is expected of your vessel — and 105, which governs the terminal you are working with and therefore what the terminal will require of you.
MARSEC levels and who sets them
MARSEC levels map onto ISPS security levels one for one, but they are set by US authority and can be raised locally without any change to the international level.
- MARSEC 1 — the normal operating condition. Baseline measures apply continuously.
- MARSEC 2 — heightened risk. Additional measures for a period; access control tightens and screening increases.
- MARSEC 3 — a probable or imminent incident. Exceptional measures for a limited period; normal operations may stop.
The Captain of the Port can raise MARSEC for a specific port or facility, which is the part operators most often miss. A vessel arriving at MARSEC 1 internationally can find the port it is entering operating at MARSEC 2 for local reasons, and its security plan has to support that step up without improvisation.
TWIC: the credential with no international equivalent
The Transportation Worker Identification Credential is a biometric card required for unescorted access to secure areas of MTSA-regulated facilities and vessels. There is no ISPS equivalent, and it surprises operators new to the trade more than any other element of the regime.
- It applies to people needing unescorted access to secure areas.
- Those without one must be escorted at the required ratio, which the facility has to resource.
- Foreign seafarers do not hold TWIC; shore leave and transit are handled through escort arrangements and the vessel's own access control.
- Contractors, surveyors and technicians attending a vessel at a US terminal frequently need one — check before they travel, not on the day.
The practical failure is a service attendance planned without checking credentials, where the technician arrives and cannot reach the vessel without an escort nobody has arranged.
What the Coast Guard actually checks
A security examination is part of the wider USCG port state control regime, and the findings look much like a security-focused inspection anywhere — with the difference that the reference is the CFR.
| Area | What is examined |
|---|---|
| Access control | Gangway watch, identity checks, records of visitors |
| Declaration of Security | Completed where required between vessel and facility |
| Drills and exercises | Conducted at required intervals with records |
| Security records | Retained for the required period and available |
| Ship Security Officer | Designated, trained and able to demonstrate the plan |
| Restricted areas | Marked and controlled as the plan describes |
The recurring failure is the same everywhere: a plan that is correct on paper and a crew that cannot demonstrate it. Examiners ask the officer on watch to explain the procedure, not to produce the binder.
Advance notice of arrival
Vessels bound for US ports must file an Advance Notice of Arrival with the National Vessel Movement Center, covering the vessel, voyage, crew, passengers and cargo. Timing depends on voyage length, and the filing must be updated when the details change.
This is a security requirement rather than a clearance formality, and it is where a great many US port calls acquire their first problem. Crew list changes after filing, an inaccurate last-port entry, or a late update are all routinely picked up, and they colour how the rest of the call is treated. Getting it right is a data-quality discipline more than a regulatory one — see the maritime single window guide for the wider pattern.
What this means for a foreign-flag operator
If your fleet trades to the US, the practical adjustments are narrow but real.
- Brief crews in MARSEC vocabulary, not only ISPS security levels — an officer answering an examiner should use the local terms.
- Confirm the MARSEC level of the specific port before arrival; it can exceed the international level.
- Resolve TWIC and escort arrangements for any attending contractor well before the call.
- File the Notice of Arrival accurately and update it when crew or cargo details change.
- Expect the Declaration of Security to be required more often than in some other jurisdictions.
None of this is difficult. It fails when a fleet treats a US call as an ISPS call with a different flag on the wall, and discovers at the gangway that the vocabulary, the credential and the paperwork are all slightly different.
Frequently asked questions
What is MTSA?
The Maritime Transportation Security Act of 2002, the United States' domestic maritime security law. It is implemented through 33 CFR Parts 101 to 106 and is enforced by the US Coast Guard rather than through the ISPS Code directly.
Is MTSA the same as the ISPS Code?
They are aligned but not identical. ISPS is the international instrument under SOLAS; MTSA is US domestic law in the Code of Federal Regulations. In a US port you are examined against the CFR, and the vocabulary differs — MARSEC levels rather than ISPS security levels, and a TWIC credential with no international equivalent.
What is a MARSEC level?
The US maritime security condition, from MARSEC 1 for normal operations to MARSEC 3 for a probable or imminent incident. It maps onto ISPS security levels, but the Captain of the Port can raise it for a specific port without any change to the international level.
What is the difference between 33 CFR 104 and 105?
Part 104 covers vessels — security plans, the Ship Security Officer, drills and records. Part 105 covers shoreside facilities and their Facility Security Plans. A visiting vessel is governed by 104 and interacts with a terminal governed by 105.
Do foreign seafarers need a TWIC?
No. TWIC is required for unescorted access to secure areas of US facilities, and foreign seafarers do not hold one. They are handled through escort arrangements. Contractors and surveyors attending a vessel at a US terminal often do need one, which should be checked before they travel.