U.S. Coast Guard

The U.S. Coast Guard is a unique military service that operates within the Department of Homeland Security during peacetime (transferring to the Navy in wartime) and performs the full spectrum of maritime law enforcement, safety, environmental protection, and national security missions. With roughly 42,000 active duty personnel and a fleet of ships and aircraft, the Coast Guard enforces federal law on U.S. waterways and up to 200 nautical miles offshore — stopping drug smuggling, human trafficking, illegal fishing, and unauthorized entry. It also sets and enforces maritime safety standards, responds to oil spills, operates search and rescue, manages the Merchant Marine licensing system, and maintains aids to navigation like lighthouses and buoys. Unlike other military branches, the Coast Guard has direct law enforcement authority — it can board and search any vessel on the high seas or in U.S. waters without a warrant. It's also the regulator of U.S. ports and waterways, meaning a disrupted supply chain or port security incident falls directly in its jurisdiction. The Coast Guard's budget (~$13 billion) and readiness have been a persistent concern given the breadth of its missions and competition for defense funding.

Current Law (2026)

Legal Authority

• 14 U.S.C. § 501 — Secretary's general powers (organize, establish, discontinue units; maintain vessels, aircraft, facilities)
• 14 U.S.C. § 504 — Commandant's general powers (operate patrols, communication systems, aids to navigation; conduct rescue)
• 14 U.S.C. § 521 — Saving life and property (rescue and aid persons, vessels, aircraft at sea and during floods)
• 14 U.S.C. § 522 — Law enforcement (board and inspect any vessel on high seas or U.S. waters; enforce federal law)
• 14 U.S.C. § 523 — Enforcement authority (carry firearms, make arrests, execute warrants)
• 14 U.S.C. § 524 — Coastwise trade enforcement (enforce cabotage laws under Title 46)
• 14 U.S.C. § 525 — Coast Guard Investigative Service (special agents with federal law enforcement authority — carry firearms, serve warrants, make warrantless arrests)
• 14 U.S.C. § 101 — Establishment of Coast Guard (created January 28, 1915; constituted as a military service and branch of the armed forces at all times)
• 14 U.S.C. § 102 — Primary duties (enforce federal law on/above/below high seas and U.S. waters; patrol to stop illegal activity; enforce safety rules; operate aids to navigation, icebreaking, and rescue services; develop readiness for military operations)
• 14 U.S.C. § 103 — Department status (Coast Guard operates within DHS; transfers to the Navy upon declaration of war or presidential direction; returns to DHS when the President directs)
• 14 U.S.C. § 302 — Commandant appointment (appointed by President with Senate confirmation for a 4-year term; may be reappointed; must be on the active-duty promotion list above captain)
• 14 U.S.C. § 308 — Chief Acquisition Officer (Rear Admiral or Senior Executive; manages all major acquisition programs; reports at the Assistant Commandant level)
• 14 U.S.C. § 311 — Captains of the port (Commandant may appoint any officer, including petty officers, as a port captain with authority over vessel movements and port safety in U.S. waters)
• 14 U.S.C. § 318 — Environmental Compliance and Restoration Program (Coast Guard environmental cleanup program for hazardous substances and oil at Coast Guard facilities and operations)
• 14 U.S.C. § 319 — Unmanned system program (within 2 years of enactment, Coast Guard must establish unmanned systems program for land-, cutter-, and aircraft-based UAS to improve mission effectiveness)
• 14 U.S.C. § 323 — Western Alaska Oil Spill Planning Criteria Program (specialized oil spill planning rules for Western Alaska; permanent civilian program manager required)
• 14 U.S.C. § 526 — Stopping vessels (if a vessel subject to seizure or search fails to stop when ordered by an authorized Coast Guard vessel or aircraft, the commander may fire at or into the vessel after reasonable effort to stop it)
• 14 U.S.C. § 541-548 — Aids to navigation (Coast Guard authorized to establish, operate, and maintain aids to maritime and air navigation; unauthorized aids prohibited with penalty; interference with aids is a crime; Secretary sets rules for lights/signals on fixed/floating structures; marking of obstructions in navigable waters; anchorage buoy placement)
• 14 U.S.C. § 561 — Polar Security Cutters (authorizes contracts for new heavy icebreakers — original program plus 3 additional Polar Security Cutters; all must be built in U.S. shipyards)
• 14 U.S.C. § 1101-1137 — Acquisition reform (acquisition directorate; Vice Commandant oversight of major programs; prohibition on lead systems integrators; program baseline breach reporting; contracting requirements)
• 14 U.S.C. § 1151/1153 — Domestic construction and repair (Coast Guard vessels must be built in U.S. shipyards; overhaul, repair, and maintenance of Coast Guard vessels in foreign shipyards prohibited)
• 14 U.S.C. § 1901-1930 — Coast Guard Academy (administration; policy on sexual harassment and violence; Board of Visitors; minority outreach; Corps of Cadets; cadet appointments, conduct, and commissioning as ensigns; marine safety curriculum)

Implementing Regulations

The USCG's commercial vessel safety inspection and certification regulations are at 46 CFR Part 71 — Inspection and Certification (66 sections across 15 subparts). Key provisions:

• § 71.01-2 (When required) — No vessel subject to inspection under 46 U.S.C. Chapter 33 may operate without a valid Certificate of Inspection (COI); vessels subject to inspection include passenger vessels (certified for more than 6 passengers), offshore supply vessels, cargo vessels of 100+ gross tons, and tank vessels — operating without a COI is a violation regardless of whether an accident has occurred
• § 71.01-10 (Period of validity) — COIs are issued for 1 year; application for renewal may be submitted by the master, owner, or agent; the COI specifies the waters upon which the vessel is authorized to operate, the number of passengers it may carry, the minimum crew, and required safety equipment
• § 71.01-5 (Posting) — The COI must be displayed under glass in a conspicuous location accessible to passengers; failure to post is itself a violation
• Subpart 71.20 — Initial Inspection: before a vessel receives its first COI, the USCG's Officer in Charge, Marine Inspection (OCMI) conducts a comprehensive initial inspection covering hull structure, propulsion system, firefighting equipment, lifesaving equipment (lifeboats, life rafts, survival suits), navigation equipment, stability documentation, crew accommodations, and sanitary conditions; initial inspections are required after major structural alterations (Subpart 71.55) and after accidents that may have compromised safety systems
• Subpart 71.25 — Annual Inspection: every vessel holding a COI must undergo a full annual inspection; USCG inspectors verify lifesaving equipment certification dates (life rafts require annual shore-side servicing), fire suppression system hydrostatic tests, navigation light functionality, stability booklet currency, and crew credential validity; the annual inspection can be conducted with the vessel afloat
• Subpart 71.50 — Drydocking: vessels must be drydocked at intervals specified in their COI (generally every 2 years for most vessels; up to 5 years for vessels enrolled in Enhanced Survey Programs); during drydocking, USCG inspects the underwater body — hull plating thickness, sea valves (through-hull fittings), propeller condition, rudder and steering gear, keel-to-waterline corrosion; underwater inspection by diver may substitute for drydocking in some circumstances
• Subpart 71.65 — Plan Approval: major modifications (adding passenger capacity, structural alterations, new propulsion systems, conversion of vessel type) require advance plan approval from the OCMI; plans must be submitted at least 30 days before commencing work; unapproved modifications invalidate the COI
• Subpart 71.75 — International Certificates: vessels operating on international voyages must also hold international safety certificates issued under the SOLAS Convention (International Convention for the Safety of Life at Sea); USCG-inspected U.S.-flag vessels may receive SOLAS Passenger Ship Safety Certificates and SOLAS Safety Equipment Certificates when they meet both U.S. and international standards simultaneously

Part 71 reflects the USCG's dual role as the flag state authority for U.S.-flag vessels (responsible for ensuring U.S.-flagged ships meet safety standards wherever they operate) and the port state control authority for foreign-flag vessels entering U.S. ports (authorized to inspect and detain foreign vessels that don't meet minimum standards). The COI system creates a direct accountability link: an inspected vessel cannot operate commercially without an active certificate, and violations discovered during inspection can result in suspension of the certificate, stranding the vessel until deficiencies are corrected. The Port State Control program — under which USCG inspects a percentage of all foreign vessels calling at U.S. ports — applies parallel standards to foreign-flag vessels, and vessels with poor inspection histories are targeted for increased scrutiny.

How It Works

The Coast Guard is the nation's oldest continuous maritime service and the only military branch within the Department of Homeland Security. It operates across 11 statutory missions that span homeland security, law enforcement, maritime safety, and environmental protection — a broader mandate than any other single federal agency.

The Coast Guard is unique among the armed forces: it operates simultaneously as a military service and a federal law enforcement agency. Personnel can board any vessel in U.S. waters or on the high seas, carry firearms, make arrests, and execute warrants — authorities other military branches cannot exercise domestically under the Posse Comitatus Act. In wartime or by presidential direction, the Coast Guard transfers from DHS to the Department of the Navy. Its 11 statutory missions divide into three categories: Homeland security — ports, waterways, and coastal security; drug interdiction; migrant interdiction; defense readiness. Safety — search and rescue; marine safety (vessel inspection, licensing, port state control); aids to navigation (lighthouses, buoys). Stewardship — marine environmental protection (oil spill response, pollution enforcement); living marine resources (fisheries enforcement); ice operations (polar icebreaking, Great Lakes).

The Coast Guard responds to approximately 20,000 search and rescue cases annually, covering maritime emergencies from recreational boating accidents to major vessel distress. Drug interdiction in the Caribbean and Eastern Pacific intercepts tons of cocaine annually; migrant interdiction operations enforce immigration law at sea; fisheries enforcement protects U.S. exclusive economic zone resources; port security protects critical maritime infrastructure — all conducted in coordination with Customs and Border Protection. The Marine Safety program inspects commercial vessels, licenses mariners, investigates marine casualties, and sets standards for vessel construction and operation, covering everything from inspecting cruise ships to certifying tugboat operators to investigating oil spills. The Coast Guard Academy in New London, Connecticut trains cadets who commission as ensigns — the service's primary officer pipeline.

The Coast Guard operates the nation's aids to navigation system under 14 U.S.C. §§ 541-548 — lighthouses, buoys, beacons, range lights, and GPS-based electronic aids guiding mariners through harbors, channels, and coastlines. Interfering with or damaging any aid to navigation is a federal crime (§ 543), and private parties must obtain Coast Guard permission before placing any aid in U.S. waters (§ 542). The environmental protection mission runs parallel: the Coast Guard leads federal response to oil spills and hazardous material releases in U.S. waters, operates the Environmental Compliance and Restoration Program (§ 318), and maintains specialized oil spill planning for the ecologically sensitive Western Alaska coastline (§ 323).

The Coast Guard is the only U.S. agency with heavy icebreaking capability — Congress authorized new Polar Security Cutters (§ 561) to replace aging vessels and maintain presence in Arctic and Antarctic waters, a mission of growing strategic importance as new shipping routes open and resource competition intensifies. Fleet modernization runs through an acquisition directorate (§§ 1101-1137) with Vice Commandant oversight over major programs including cutters, aircraft, and electronics. All Coast Guard vessels must be built in U.S. shipyards (§ 1151) and may not be overhauled or repaired in foreign yards (§ 1153).

How It Affects You

If you're a recreational boater, the Coast Guard is simultaneously your safety regulator, your rescuer, and your law enforcement officer on the water. Federal law requires specific safety equipment on every recreational vessel: Coast Guard-approved life jackets for each person aboard, a fire extinguisher (for enclosed spaces or any gas-powered boat), visual distress signals, and navigation lights for operating after dark. The Coast Guard can board your vessel without a warrant on any navigable water to verify compliance. Boating under the influence (BUI) is a federal offense — the legal standard is a BAC of 0.08% or greater, same as driving, and Coast Guard enforcement is active in coastal waters and major recreational boating areas. If you need help on the water, VHF Channel 16 is the universal hailing and distress frequency monitored by the Coast Guard 24/7; you can also call 1-800-368-5647 (non-emergency) or dial 911 for land-based emergency coordination. The Coast Guard's free Vessel Safety Check program (boatus.org/cg/vsc) lets you get a voluntary inspection from a licensed Auxiliary examiner — a good way to verify your boat meets all requirements before an enforcement boarding. The American Boating Association (americanboating.org) and BoatUS (boatus.org) track safety regulation changes affecting recreational boaters.

If you're a commercial mariner — working on a cargo ship, tug, ferry, fishing vessel, or any commercial vessel on U.S. navigable waters — your career depends on a Coast Guard-issued Merchant Mariner Credential (MMC). The MMC combines what were previously separate documents (Z-card, license, STCW certificate) into a single credential that authorizes your position and watch-keeping duties. To get or renew an MMC, you apply through the National Maritime Center (uscg.mil/nmc), which requires documentation of sea service, completed training courses, a physical examination, and a drug test. The STCW Convention (International Convention on Standards of Training, Certification and Watchkeeping) sets international competency standards that your MMC must reflect for service on vessels over 200 gross tons on international voyages. The Coast Guard investigates marine casualties and can suspend or revoke your MMC for drug/alcohol violations, negligence, incompetence, or misconduct — a suspended credential means you can't work. If you face a suspension or revocation proceeding, you have the right to a hearing before an Administrative Law Judge; the Seafarers International Union (seafarers.org) and Masters, Mates & Pilots (bridgedeck.org) provide legal resources for credentialed mariners.

If you're in the commercial fishing industry, the Coast Guard operates as the enforcement arm of federal fisheries management in the U.S. Exclusive Economic Zone — the 200-nautical-mile band offshore where U.S. law governs all fishing. Coast Guard cutters and aircraft patrol the EEZ, board fishing vessels, verify permits and catch documentation, and enforce National Marine Fisheries Service (NMFS) regulations including closed area restrictions, catch limits, gear restrictions (mesh size, excluder devices), and observer program requirements. A violation of fishing regulations can result in permit suspension, civil penalties up to $100,000 per violation for serious cases, and criminal prosecution for the most egregious offenses. The Coast Guard also enforces the Jones Act's coastwise fishing restriction — only U.S.-built, U.S.-flagged, U.S.-crewed vessels may fish commercially in U.S. waters. If you operate in the EEZ, maintain meticulous logbooks: the Coast Guard's inspection will focus on whether your catch documentation matches what's onboard. The National Fisheries Institute (aboutseafood.com) and regional fishery management councils publish compliance guides for each fishery's specific requirements.

If you're a port operator, terminal manager, or waterfront facility owner, the Coast Guard's Captain of the Port (COTP) has broad authority over your operations under Title 33 of the CFR. The Maritime Transportation Security Act of 2002 (MTSA) — which the Coast Guard implements — requires any "MTSA-regulated facility" (those that handle certain cargo, passengers, or dangerous goods) to develop a Facility Security Plan (FSP) approved by the COTP, designate a Facility Security Officer, and maintain an access control system that prevents unauthorized persons from reaching secure areas of the port. The Coast Guard conducts facility inspections and can issue a Notice of Violation with civil penalties up to $25,000 per day for noncompliance. Beyond security, the COTP controls vessel traffic in the port through safety and security zones — during special events, hazardous cargo operations, or emergency conditions, the COTP can restrict or halt vessel movements entirely. The COTP also oversees anchorage and waterway use, and any significant dredging, construction, or alteration of navigable waters requires a Coast Guard permit under Section 10 of the Rivers and Harbors Act (usace.army.mil for Army Corps permits, uscg.mil for Captain of the Port coordination).

State Variations

The Coast Guard is a federal service with nationwide jurisdiction over navigable waters. State marine patrol and fish and wildlife agencies have concurrent jurisdiction in state waters (generally 3 nautical miles from shore, 9 in some Gulf Coast states). States license recreational boaters and enforce state boating laws, while the Coast Guard enforces federal requirements.

Implementing Regulations

• 33 CFR Part 1 — Coast Guard organization (§§ 1.01-50, 1.05-5 — delegation to district commanders, Marine Safety and Security Council)

• 33 CFR Part 100 — Safety and security zones (§ 100.10 — Coast Guard-State agreements for regattas and marine events)

• 33 CFR Part 125 — Port security (§§ 125.11, 125.12 — Coast Guard port security cards, period of validity)

• 33 CFR Part 140 — OCS activities (§ 140.101 — inspection by Coast Guard marine inspectors)

• 33 CFR Part 149–150 — Deepwater ports (equipment requirements, operations manuals, Coast Guard-approved equipment)

• 33 CFR Part 83 — Inland Navigation Rules (37 sections — the U.S. equivalent of the International Regulations for Preventing Collisions at Sea (COLREGS), applicable to all vessels on U.S. inland waters including rivers, lakes, harbors, and the Great Lakes; implements 33 U.S.C. § 2071 (the Inland Navigational Rules Act of 1980, as amended); the rules govern collision avoidance, vessel lighting, sound signals, and navigation in restricted conditions):

  • Rules 1–3 (Application and Definitions): Part 83 applies to all vessels on U.S. inland waters seaward to the COLREGS Demarcation Lines; where COLREGS applies (offshore), Rule 10 (traffic separation schemes) takes over; a vessel is defined broadly — any watercraft including non-displacement craft and seaplanes; a power-driven vessel means any vessel propelled by machinery; a vessel not under command (NUC) means one unable to maneuver due to exceptional circumstances; restricted in ability to maneuver (RAM) covers dredges, cable-laying vessels, and vessels engaged in diving or replenishment operations underway

  • Rule 5 (Lookout): every vessel must at all times maintain a proper lookout by sight and hearing — the foundational rule underlying nearly all collision cases; failure to maintain a proper lookout is the most commonly cited Coast Guard finding in marine casualty investigations

  • Rule 6 (Safe Speed): vessels must proceed at a safe speed allowing proper action to avoid collision and stop within appropriate distance; factors include visibility, traffic density, vessel maneuverability, background light, depth, and the presence of radar

  • Rules 7–8 (Risk of Collision and Action to Avoid): risk of collision exists if compass bearing of an approaching vessel does not appreciably change; action to avoid collision must be large enough and made in ample time; a vessel must not alter course to port for a vessel forward of the beam

  • Rule 9 (Narrow Channels): vessels must keep as far to the starboard side of a narrow channel as safe; a vessel less than 20 meters or a sailing vessel must not impede a vessel that can only navigate safely within the channel; no anchoring in a narrow channel

  • Vessels In Sight of One Another — Rules 12–18 (the crossing/overtaking/head-on hierarchy):

    • Rule 12: between sailing vessels, the leeward vessel has right of way; on same tack, the windward vessel gives way
    • Rule 13 (Overtaking): an overtaking vessel must keep clear; a vessel is overtaking when approaching another from more than 22.5° abaft the beam (within the vessel's sternlight arc)
    • Rule 14 (Head-On): two power-driven vessels meeting head-on must both alter course to starboard
    • Rule 15 (Crossing): the vessel with the other vessel on her starboard side is the give-way vessel; the vessel on the port side is the stand-on vessel
    • Rule 16: the give-way vessel must take early, substantial action to keep clear
    • Rule 17: the stand-on vessel must maintain course and speed until collision is imminent; only then may she take action to avoid
    • Rule 18 (Responsibilities Between Vessels — the priority hierarchy): a power-driven vessel underway must give way to: (1) NUC vessels, (2) RAM vessels, (3) vessels constrained by draft, (4) fishing vessels, (5) sailing vessels; this hierarchy does not relieve the burdened vessel of its own collision-avoidance obligations

  • Rules 20–31 (Lights and Shapes): vessels must display navigation lights between sunset and sunrise and in restricted visibility; a masthead light (white, visible 225°) is forward; a stern light (white, 135°) is aft; sidelights are red (port) and green (starboard); a towing light is yellow in the sternlight position; specific light configurations distinguish vessel type and operational status — fishing vessels vs. trawlers, vessels towing vs. pushing, NUC vessels (two red lights, vertical), RAM vessels (red-white-red vertical), sailing vessels (red over green at masthead or sidelights only), pilot vessels (white over red), anchored vessels (anchor light)

  • Rules 32–37 (Sound and Light Signals): in restricted visibility every vessel must sound a prolonged blast (4–6 seconds) at intervals not exceeding 2 minutes while underway; a vessel at anchor sounds a rapid bell for 5 seconds every minute; maneuvering signals: one short blast = altering course to starboard, two short blasts = altering course to port, three short blasts = operating astern propulsion; the danger signal (five or more short blasts) indicates doubt about the other vessel's intentions

  The inland rules differ from COLREGS in several practical respects: inland rules require an agreement between vessels before an overtaking maneuver in a narrow channel (the overtaking vessel requests via whistle; the other vessel assents with the same signal); the concept of "Western Rivers rules" (Rule 9(a)(ii)) allows downstream vessels right of way over upstream vessels on certain rivers. Recent amendments: 79 FR 37912 (July 2014) — updated Annexes to align with 2009 COLREGS amendments on lights and shapes; 80 FR 44280 (July 2015) — technical corrections to Annex I (positioning of lights) and Annex III (technical specifications for sound signals)

• 33 CFR Part 167 — Offshore Traffic Separation Schemes (70 sections): the federally established shipping lanes at major U.S. port approaches. A traffic separation scheme (TSS) divides vessel traffic at busy chokepoints into one-way lanes — inbound traffic in one lane, outbound in another — separated by a buffer zone, with precautionary areas (defined mixed-traffic zones) where shipping lanes converge. The TSS concept originated from COLREGS (the International Regulations for Preventing Collisions at Sea); § 167.10 requires vessels navigating a U.S. offshore TSS to comply with COLREGS Rule 10, which prohibits crossing a traffic lane except at right angles, prohibits anchoring in a lane, and requires vessels to join or leave schemes at the ends of lanes rather than cutting across. Subpart B of Part 167 (65 sections) specifies geographic coordinates for each U.S. scheme — including approaches to Narragansett Bay and Buzzards Bay (Cape Cod Canal), the Strait of Juan de Fuca (Puget Sound gateway), approaches to New York, Boston, Tampa Bay, Los Angeles, and San Francisco. The most recent major update (75 FR 70827, November 2010) revised coordinates and precautionary area boundaries for several schemes to accommodate vessel size growth (container ship beam and draft increases). Violations of COLREGS Rule 10 within a U.S. TSS can expose vessel officers to Coast Guard civil penalty proceedings under 33 U.S.C. § 1608

• 46 CFR Parts 1–199 — Shipping (comprehensive vessel inspection, certification, and safety standards administered by the Coast Guard). Key Parts within the 46 CFR marine safety framework:

  • 46 CFR Part 153 — Ships Carrying Bulk Liquid, Liquefied Gas, or Compressed Gas Hazardous Materials (203 sections — the safety standards for the U.S. and foreign chemical tanker fleet operating in U.S. waters; covers vessels carrying bulk quantities of hazardous liquids and liquefied gases other than the cryogenic LNG/LPG cargoes covered by Part 154; implements IMO requirements and MARPOL Annex II):
    • Subpart A — General (14s): applicability to U.S.-flagged ships and foreign ships operating in U.S. waters carrying bulk liquid, liquefied gas, or compressed gas hazardous materials; Certificate of Inspection (for U.S. vessels) or Certificate of Compliance (for foreign vessels) required before entering U.S. ports with regulated cargoes; foreign vessels must carry an IMO Certificate issued under the International Bulk Chemical Code (IBC Code) or Gas Carrier Code; the Coast Guard Officer in Charge, Marine Inspection (OCMI) administers port state control for foreign chemical tankers
    • Subpart B — Design and Equipment (110s — the technical core): three containment system types (Type I, II, III) defined by the hazard level of the cargo — Type I (most hazardous, e.g., carbon disulfide, chlorosulfonic acid) requires the most protective hull design with cargo tanks located away from the ship's shell; Type II (medium hazard, e.g., methanol, styrene, xylene) requires less protection; Type III (low hazard, e.g., vegetable oils, lubricating oils) may use standard cargo tanks anywhere in the hull; cargo piping restrictions keep hazardous lines out of accommodation and machinery spaces; cargo pump room ventilation; emergency equipment (stretchers, safety equipment lockers, showers and eyewash fountains at cargo transfer points); ballast system isolation from cargo systems to prevent contamination
    • Subpart C — Operations (75s): pre-transfer conference between vessel and terminal before any cargo transfer; transfer hose and loading arm pressure ratings must exceed maximum cargo transfer pressure; emergency shutdown systems (ESD) that automatically close cargo valves on alarm; slop tank management for cargo residues; cargo vapor control systems where required by cargo toxicity; personnel protective equipment (full chemical suit, SCBA) for certain toxic cargoes; Tank Inspection Clause — cargo tanks must be inspected before each cargo for residues from prior cargo incompatible with the new cargo
  • 46 CFR Part 154 — Safety Standards for Self-Propelled Vessels Carrying Bulk Liquefied Gases (245 sections — the primary Coast Guard safety regulation for LNG carriers, LPG tankers, and other vessels transporting liquefied gas in bulk; implements IMO's International Gas Carrier Code standards into U.S. law):
    • Subpart A — General (15 sections): applicability (U.S.-flagged vessels and foreign vessels in U.S. ports carrying bulk liquefied gas in cargo tanks of 150 m³ or more); definitions of cargo containment systems (membrane tanks, moss sphere tanks, prismatic tanks — each with distinct structural and insulation requirements); Coast Guard Officer in Charge, Marine Inspection (OCMI) as primary inspection authority; certificate of inspection requirement
    • Subpart B — Inspections and Tests (2 sections): initial and periodic inspection requirements; gas-free certification before entry to cargo spaces; pressure testing of containment systems
    • Subpart C — Design, Construction and Equipment (175 sections — the technical core): cargo containment system design — type A (free-standing prismatic tanks, highest structural integrity), type B (independent tanks with partial secondary barrier, dominant design on LNG carriers), type C (pressure vessel tanks for high-pressure gases, LPG carriers), and membrane systems (thin metallic membranes supported by insulation — GTT membrane technology used on most modern LNG carriers); secondary barrier requirements to contain cargo for 15 days in the event of primary containment failure; cargo tank materials suitable for cryogenic temperatures (Invar, 9% nickel steel, stainless steel for LNG at −162°C); cargo piping and valve standards; inerting systems to prevent flammable atmosphere in cargo tank spaces; gas detection systems with continuous monitoring and alarms
    • Subpart D — Special Design and Operating Requirements (14 sections): minimum distances between cargo tanks and ship's shell; requirements for vessels carrying specific cargoes (anhydrous ammonia — toxic vapor management; vinyl chloride — inhibitor requirements; LPG — pressure relief valve settings)
    • Subpart E — Operations (39 sections): cargo transfer operations — pre-transfer conference, transfer hose/arm pressure ratings, emergency shutdown systems; cargo loading and unloading procedures; thermal limits during cooldown of tanks; emergency shutdown system (ESD) — automatic closure of cargo valves when heat/fire detected or manual activation at multiple stations; training requirements for cargo officers and ratings handling gas cargoes; safety management system integration

• 46 CFR Part 4 — Marine Casualties and Investigations: the Coast Guard's comprehensive framework for reporting marine accidents, conducting investigations, and requiring chemical testing of crew members following serious incidents. Key provisions:

  • § 4.03-1 — Marine casualty or accident (defined): any casualty involving a vessel other than a public vessel that results in death, injury, material damage, loss, or abandonment at sea; the definition covers U.S.-flagged vessels wherever they operate and foreign vessels in U.S. navigable waters
  • § 4.03-2 — Serious marine incident (defined): the subset of casualties triggering mandatory chemical testing — includes any marine casualty involving a death; an injury requiring professional medical treatment beyond first aid; property damage exceeding $25,000; actual or constructive total loss of any vessel; or a discharge of oil or hazardous materials causing significant environmental harm
  • § 4.05-1 — Notice of marine casualty: the owner, agent, master, operator, or person in charge must immediately notify the nearest Coast Guard Marine Safety or Marine Inspection Office after addressing immediate safety concerns; this is a parallel obligation to the NTSB notification requirement for certain marine accidents (NTSB and Coast Guard coordinate investigations under the joint investigation procedures in Subpart 4.40)
  • § 4.05-10 — Written report: a written accident report must be filed within 5 days of any casualty required to be reported under § 4.05-1; the report must include vessel identification, nature of the casualty, time and location, persons involved, and a description of events
  • § 4.05-12 — Alcohol and drug use determination: for every casualty reported under § 4.05-10, the marine employer must determine whether alcohol or drug use was a factor; if the casualty meets the "serious marine incident" definition, chemical testing is mandatory
  • § 4.05-15 — Voyage records retention: the owner, agent, master, or person in charge of any vessel involved in a casualty must retain all voyage records (logbooks, charts, navigation data, electronic records) until the Coast Guard has completed its investigation and authorized their disposition; premature destruction of voyage records is a federal offense
  • § 4.06-1 — Marine employer responsibilities at time of casualty: the marine employer must immediately take steps to determine if a serious marine incident has occurred; must collect initial alcohol test results before 2 hours have elapsed, and drug test specimens before 32 hours have elapsed; these hard deadlines ensure testing captures impairment while metabolites are still detectable
  • § 4.06-3 — Mandatory chemical testing: for serious marine incidents, all individuals directly involved must submit to blood-alcohol testing (BAC cutoff: 0.04% for duty impairment — half the standard DUI threshold) and urine drug testing; refusal to submit to chemical testing is itself a violation that can result in suspension or revocation of a mariner's credential
  • § 4.06-15 — Testing equipment: marine employers must keep alcohol testing devices on board and available at all times for vessels in commercial service; the devices must be Coast Guard-approved or state-police-certified
  • Subpart 4.07 — Investigations: the investigating officer has authority to examine witnesses under oath, take sworn statements, require production of records, and recommend corrective action; investigation reports are made available to the public with appropriate redactions for safety security information
  • Subpart 4.40 — Coast Guard/NTSB joint investigations: certain marine casualties (particularly those involving deaths, or major disasters) are jointly investigated by the Coast Guard and the National Transportation Safety Board; the joint protocol specifies how the two agencies coordinate evidence collection, witness access, and report publication

  Part 4 represents a critical interface between maritime safety and maritime law: a vessel owner's obligation to report a casualty, maintain records, and submit crew to chemical testing exists alongside crew members' constitutional rights, their right to STCW-mandated rest, and their right to union representation. Calibrating these obligations is an ongoing tension in Coast Guard administration.

• 33 CFR Part 174 — State Numbering and Casualty Reporting Systems: the federal standards that state recreational boating safety programs must meet to remain approved and receive federal boating safety funding under the Federal Boat Safety Act of 1971 (46 U.S.C. §§ 13101–13110). Rather than the USCG directly numbering every boat in America, Congress established a cooperative system: states run their own numbering and accident reporting programs, but those programs must conform to USCG minimum standards.

  • § 174.1 — Applicability and preemptive effect: Part 174 establishes minimum standards that states must incorporate into their numbering and casualty reporting systems; a state system that meets or exceeds these standards is "approved" and qualifies for federal funding; the regulation preempts inconsistent state requirements in areas where USCG has set minimum standards
  • § 174.11 — State numbering system requirements: every state numbering system must require the registration of vessels to which 33 CFR § 173.11 applies (generally all motorized vessels and sailboats of a certain size used on state waters); state-issued registration numbers must conform to USCG's standardized format (state abbreviation + letter-number-letter sequence); numbers must be displayed on the vessel's bow in prescribed size and color-contrast format; state records must be maintained in a searchable database accessible to USCG and law enforcement; USCG's national database (the Vessel Documentation and Numbering System) aggregates state records for law enforcement and search-and-rescue use
  • § 174.101 — Casualty reporting system requirements: state programs must require the reporting of vessel casualties and accidents involving vessels subject to 33 CFR § 173.51 — any collision, capsizing, or accident resulting in a death, disappearance, injury requiring medical treatment, or property damage exceeding a monetary threshold (currently $2,000); the state system must track all mandatory reporting elements so that data can be aggregated into USCG's national Boating Accident Report Database (BARD)
  • § 174.105 — Owner/operator casualty reporting: state systems must require boat owners or operators to file an accident report within specified time limits — immediately for fatalities or missing persons; within 48 hours for injuries requiring medical treatment; within 10 days for all other reportable accidents; the deadlines mirror the federal requirements in Part 173
  • § 174.107 — Required report form content: state accident report forms must capture the required data elements in Part 173 — vessel description, operator information, alcohol/drug involvement, cause of accident, nature and extent of injury and property damage, weather and water conditions
  • § 174.121 — Forwarding casualty reports to USCG: within 30 days of receiving an accident report, the state must forward the information (paper or electronic) to the USCG National Boating Safety Division; USCG aggregates state data into BARD, the national database used to identify boating accident patterns, evaluate safety equipment effectiveness, and target boating safety education programs
  • § 174.123 — Annual vessel report: before March 1 each year, each state with an approved numbering system must submit to USCG the total number of vessels registered in the state and other summary statistics; USCG uses this data to calculate each state's share of the federal boating safety grant program under 46 U.S.C. § 13104 — the funding formula is based partly on vessel registration counts, creating a financial incentive for states to maintain complete registries

  Part 174's cooperative federalism structure is the backbone of recreational boating data in the United States. USCG's annual Recreational Boating Statistics report — which tracks deaths, injuries, and property damage from boating accidents — is built from state data forwarded under Part 174. The data drives boating safety priorities: it shows that operator inattention, improper lookout, operator inexperience, excessive speed, and alcohol use cause the majority of accidents, and that lack of a life jacket is the leading contributing factor in drowning deaths. States that maintain approved numbering and reporting systems receive annual federal boating safety grants; states that fail to maintain approval risk losing this funding. No major amendments to Part 174 in recent years; the dollar threshold for reportable property damage was last updated to $2,000.

• 46 CFR Part 28 — Requirements for Commercial Fishing Industry Vessels (110 sections across 8 subparts — the Coast Guard's safety equipment and operational requirements for U.S. commercial fishing vessels, including crab boats, trawlers, longliners, gillnetters, and aquaculture support vessels; commercial fishing is one of the most dangerous occupations in the United States, with fatality rates exceeding most other industries; Part 28 implements the Commercial Fishing Industry Vessel Safety Act and applies to all uninspected commercial fishing industry vessels):

  • § 28.30 — Applicability and preemptive effect: Part 28 applies to all U.S.-flag vessels not otherwise inspected (commercial fishing, fish tender, and fish processing vessels); USCG regulations preempt inconsistent state safety requirements; vessels operating in state waters are still subject to the federal framework
  • §§ 28.100–28.165 — Subpart B — Lifesaving equipment for all vessels: every commercial fishing vessel must carry PFDs or immersion suits (one per person aboard); ring life buoys scaled by vessel length (table 28.115); survival craft — inflatable liferaft scaled by vessel length and operating area (table 28.120); survival craft must be stowed so as to float free if the vessel sinks (§ 28.125 — automatic inflation via hydrostatic release); survival craft equipment pack (§ 28.130 — water, signaling devices, fishing kit, rations); distress signals per operating area (table 28.145 — flares, dye markers, EPIRB, mirror by area); EPIRB — an emergency position-indicating radio beacon required on each vessel, registered with NOAA so it transmits the vessel's identity when activated
  • §§ 28.200–28.270 — Subpart C — Additional requirements for documented vessels: vessels operating beyond coastal waters must carry fireman's outfits and SCBA when carrying more than 49 persons (§ 28.205); first aid manual and medicine chest scaled to crew size (§ 28.210); guards on machinery to prevent entanglement (§ 28.215); VHF radiotelephone required (§ 28.245 — Channel 16 for distress; vessels on open sea waters must also carry an SSB radio); bilge pumps adequate to drain any watertight compartment (§ 28.255); GPS or electronic position-fixing device required on vessels 79+ feet operating beyond coastal waters (§ 28.260); safety drills — the master must ensure crew receives instruction on use of lifesaving and fire-fighting equipment; orientation for each new crew member before departure (§ 28.270)
  • §§ 28.300–28.365 — Subpart D — Requirements for vessels with a keel laid after August 29, 1991 or major conversions: newer vessels or those undergoing major conversion must meet construction and equipment standards beyond the basic requirements — survival craft launching requires a gate or opening in rails adjacent to craft stowage (§ 28.310); fire pumps required on vessels 36+ feet (§ 28.315); fixed gas fire extinguishing systems in machinery spaces on vessels 79+ feet (§ 28.320); smoke detectors in accommodation spaces (§ 28.325); fuel system safety — fuel tanks, fuel lines, and ventilation of engine spaces must meet specific standards to prevent explosion (§§ 28.335–28.340); two-generator redundancy for vessels that rely on electricity for essential loads (§ 28.355); electrical wiring in wet areas must be waterproof (§ 28.350)
  • §§ 28.1100–28.1115 — Subpart K — Citizenship waiver: 46 U.S.C. § 8103 generally requires U.S. citizenship for crew on documented commercial fishing vessels; vessel owners may request a waiver from the USCG Commandant when U.S. citizens are not available; the Coast Guard must act on waiver requests within 30 days, and if it fails to do so, the waiver is deemed approved (§ 28.1110 — the 30-day default-approval provision reflects fishing industry labor shortages); waivers are documented in the USCG tracking system

  Part 28 reflects the Coast Guard's response to consistently high commercial fishing fatality rates — Alaska crab fishing, North Atlantic groundfish, and Gulf of Mexico shrimping have historically claimed dozens of lives per year through capsizing, man-overboard, falls, and vessel fires. The survival craft float-free requirement (§ 28.125) and automatic EPIRB activation are designed to save crew who cannot manually deploy equipment in a rapid sinking. The 1991 amendments that added Subpart D construction requirements for newer vessels followed high-profile fishing vessel disasters in the late 1980s. Part 28 applies only to uninspected vessels; commercial fishing vessels carrying fewer than 16 passengers on inspected voyages may be subject to additional USCG inspection requirements under 46 CFR Subchapters T and C.

• 46 CFR Part 35 — Tank Vessel Operations (85 sections — the operational rules governing how tank ships and tank barges carrying flammable, combustible, or hazardous liquid cargoes must be operated; covers cargo handling, safety rules, posting requirements, and special operating conditions). Key subparts and provisions:

  • Subpart 35.01 — General Provisions; Special Operating Requirements: § 35.01-1 — Hot work prohibition: no welding, burning, riveting, or other fire-producing work may begin on or near cargo tanks, fuel tanks, or connected piping until an inspection certifies the space is safe; the NFPA 306 "Standard for the Control of Gas Hazards on Vessels to be Repaired" governs the inspection protocol; Coast Guard or an approved Marine Chemist must issue a certificate before work proceeds. § 35.01-10 — Shipping papers: every loaded tank vessel must carry a bill of lading or manifest listing the consignee, cargo type, grade, and approximate quantity; applies to unmanned barges via the towing vessel's logbook. § 35.01-2 — Federal preemption: Part 35 regulations preempt state or local regulations in the same field — ensuring uniform operational standards for tank vessels operating across state jurisdictions
  • Subpart 35.10 — Fire and Emergency Requirements (4 sections): fire-extinguishing equipment must be maintained; emergency repairs to firefighting apparatus require advance notice to the Officer in Charge, Marine Inspection (OCMI) — reinforcing that tank vessels carry specialized fire suppression capability matched to their cargo hazards
  • Subpart 35.20 — Navigation (9 sections): navigation requirements specific to tank vessels — including watch-keeping standards and the duty to avoid situations where cargo hazards could compound navigational risk
  • Subpart 35.30 — General Safety Rules (9 sections): smoking, open flames, and ignition sources restricted in way of cargo spaces; personnel protective equipment requirements when working in or near cargo areas; flashlight specifications referenced via ASTM F1014 for use in hazardous spaces
  • Subpart 35.35 — Cargo Handling (18 sections — the most operationally significant subpart): pre-transfer procedures, cargo tank inspection before each loading to check for residues incompatible with the incoming cargo, loading and discharge rate limits, hose connection standards, and emergency shutdown obligations during cargo operations; requires that the master or officer in charge personally supervise or ensure supervision of cargo transfers involving flammable or hazardous liquids
  • Subpart 35.40 — Posting and Marking Requirements (14 sections): tank ships and barges must post operational notices, emergency instructions, and cargo-specific safety placards in required locations; postings must be in English (with translation required where the crew's working language is not English); markings must remain legible throughout the voyage

  Part 35 was substantially updated in November 2024 (89 FR 93138) — the most significant overhaul in decades — consolidating hot work procedures, updating cargo tank inspection requirements, and aligning posting requirements with current SOLAS and IBC Code standards. The rule preempts state regulation in the same field (§ 35.01-2), reflecting the federal government's exclusive jurisdiction over tank vessel operations in U.S. navigable waters.

• 33 CFR Part 20 — Rules of Practice, Procedure, and Evidence for Formal Administrative Proceedings (81 sections — the procedural framework governing all Coast Guard administrative hearings: civil penalty proceedings under statutes such as OPA and CERCLA, suspension and revocation (S&R) proceedings for merchant mariners' credentials, and port security penalty proceedings under MTSA). Key subparts and provisions:

  • Subpart B — Administrative Law Judges (§§ 20.201–20.206): the ALJ is assigned by the Chief ALJ, cannot be supervised by officers who investigate or represent the Coast Guard (§ 20.206 separation of functions), and may be challenged for bias; ex parte communications are governed by APA § 557(d); § 20.202 gives the ALJ authority to administer oaths, issue subpoenas, take depositions, and order the production of records
  • Subpart C — Parties, Representatives, and Rights: § 20.301 — a party may appear without counsel, with an attorney, or with a duly authorized representative; § 20.302 — all documents must be filed with the Coast Guard ALJ Docketing Center in Arlington, Virginia
  • Subpart J — Appeals to the Commandant: § 20.1001 — any party may appeal the ALJ's decision by filing a notice of appeal with the Docketing Center; § 20.1003 — the appellant files an appellate brief with the Commandant; § 20.1004 — the Commandant reviews for ALJ error and may affirm, modify, reverse, or remand; the Commandant's decision is the final agency action
  • Subpart K — Finality and Post-Decision Petitions: § 20.1101 — unless appealed, an ALJ's civil penalty order becomes final 30 days after service; § 20.1102 — persons who were not given a hearing on a civil penalty complaint may petition the Commandant to set the decision aside and grant a hearing within 30 days
  • Subpart L — Expedited Hearings for Temporarily Suspended Credentials: § 20.1201 — when the Coast Guard suspends a mariner's credential without a prior hearing (emergency 45-day suspension under 46 U.S.C. § 7702(d)), the ALJ immediately schedules an expedited hearing; § 20.1205 allows the mariner to move for return of the temporarily suspended credential at any point during the expedited hearing
  • Subpart M — Special Evidence Rules for S&R Proceedings: § 20.1303 — logbook extracts authenticated by Coast Guard officers are admissible; § 20.1305 — official logbook entries made in substantial compliance with 46 U.S.C. § 11501 are admissible and may be given substantial weight; § 20.1307 — a federal court conviction is conclusive in an S&R proceeding for the same offense; § 20.1311 — admissions made by a respondent during a Coast Guard marine casualty investigation under Part 4 may not be used against the respondent in an S&R proceeding, protecting the willingness of mariners to cooperate with accident investigations; § 20.1315 — prior disciplinary records less than 10 years old are admissible in aggravation or mitigation during penalty phase

  Part 20 hearings arise most commonly from: (1) civil penalty proceedings for oil spill and marine pollution violations (OPA, CERCLA, MARPOL Annex I); (2) mariner S&R proceedings following positive chemical tests, DUI convictions, or serious marine casualties; and (3) port security civil penalty proceedings under MTSA. Mariners in S&R proceedings have the right to counsel, to cross-examine witnesses, and to present evidence in their defense — rights analogous to those in federal court but in an administrative forum. The separation-of-functions requirement (§ 20.206) is a structural protection ensuring the ALJ remains independent from the investigating officers who built the case.

• 33 CFR Part 25 — Claims (50 sections — the Coast Guard's administrative claims process for individuals seeking compensation for property damage or personal injury caused by the negligence of USCG personnel or equipment; authority: 14 U.S.C. § 503, which grants the Commandant authority to adjudicate claims and settle them out of court up to statutory limits). Part 25 implements the administrative exhaustion requirement of the Federal Tort Claims Act: before suing the United States in federal court for a USCG-related injury or property loss, a claimant must first file an administrative claim with the USCG and allow it six months to adjudicate. Key provisions:

  • § 25.107 — Who may present claims: a property owner, injured person, or legal representative (including an insurer in subrogation) may present a claim; corporate entities may file; insurers who have paid a covered loss may file in subrogation if the insured's rights have been properly assigned
  • § 25.111 — Action by claimant: the claimant must submit a written claim to the USCG district office with jurisdiction over the location of the incident; no particular form is required, but the claim must state the amount of compensation sought; failing to state a sum-certain amount is a common error that causes claims to be returned without action
  • § 25.113 — Contents of claim: the claim must describe the incident, the damages suffered, and the basis for asserting USCG liability (generally, that a USCG employee acting in the scope of duty caused the damage through negligence); claims for personal injury must include a medical report; claims for property damage must include documentation of value and repair costs
  • §§ 25.117–25.119 — Evidence supporting claims: for personal injury or death claims, the claimant must provide medical records, physician statements, documentation of lost wages, and other evidence of damages; for property damage, repair estimates, bills, and an independent appraisal (if the claim exceeds a threshold amount) are required; incomplete documentation is the most common reason for delayed adjudication
  • § 25.123 — Settlement and notice: once the USCG makes a final determination — either offering a settlement or denying the claim — it notifies the claimant in writing; acceptance of a settlement offer releases all further claims arising from the same incident
  • § 25.125 — Appeal: a claimant who disagrees with the settlement offer or denial may appeal to the next higher USCG authority; Part 25's internal appeal exhausts administrative remedies and preserves the right to file suit in federal court under the FTCA
  • § 25.127 — Reconsideration: after an appeal decision, the claimant may petition for reconsideration once before the right to file in court accrues; the six-month administrative clock stops running while reconsideration is pending

  The most common Part 25 claims involve: (1) vessel collisions with USCG cutters or aids to navigation maintained by the USCG; (2) damage to docks or waterfront property during USCG operations; (3) personal injury to persons aboard USCG vessels or at USCG facilities. The $500 small-claims settlement authority allows the Commandant to settle minor claims without referral to higher authority — streamlining resolution of routine incidents. Claims above settlement authority limits must be forwarded to the Department of Justice. No major amendments to Part 25 in recent years.

• 33 CFR Part 126 — Handling of Dangerous Cargo at Waterfront Facilities (21 sections — the Coast Guard's permit and safety framework governing waterfront facilities that handle packaged or bulk-solid dangerous cargo, including explosives, flammable liquids, poisons, and corrosives loaded onto or discharged from vessels; authority: 46 U.S.C. § 70034):

  • § 126.13 — Designation of waterfront facilities: before a facility may handle any "designated dangerous cargo" (DDC — a defined category of the most hazardous materials), the Captain of the Port (COTP) must officially designate the facility as approved for that handling; designation requires the facility to meet specific physical and operational conditions
  • § 126.15 — Conditions for designation: designated facilities must maintain fire extinguishing equipment, emergency lighting, and communication systems; access controls must limit entry to authorized personnel; facility layout must provide clear separation between cargo and ignition sources; conditions must be maintained continuously (not just at time of designation)
  • § 126.16 — "Facility of particular hazard": facilities handling the most sensitive DDC categories (explosives, certain poisons) must meet elevated conditions — enhanced fire protection, additional exclusion zones, and more frequent inspection; designation as a facility of particular hazard triggers higher compliance scrutiny
  • § 126.17 — Permits required for DDC handling: each individual transaction involving DDC — every loading or discharge — requires a separate permit from the COTP; permits are transaction-specific and expire at the conclusion of the loading or discharge operation
  • § 126.19 — Permit issuance: permits are issued on application by the facility owner or operator; the COTP evaluates compliance with conditions in §§ 126.15–126.16 before approving; the COTP may impose additional conditions on a specific transaction (e.g., weather restrictions, time-of-day limits)
  • § 126.25 — Penalties for unpermitted DDC handling: handling, loading, or discharging DDC without a permit is a federal violation regardless of compliance with all physical conditions; the permit requirement is independent of compliance with substantive safety standards
  • § 126.27 — General permit for other dangerous cargo: for dangerous cargo that is not DDC (a broader category — hazardous materials that do not meet the DDC threshold), Part 126 issues a standing general permit authorizing handling without a transaction-specific permit, provided the facility complies with applicable safety standards; the general permit framework allows normal commercial operations for most hazardous cargo while reserving the per-transaction permit requirement for the highest-hazard materials
  • § 126.28 — Ammonium nitrate special requirements: ammonium nitrate (used in fertilizers and as a blasting agent) receives specific handling requirements due to its explosion risk when contaminated or exposed to heat; ammonium nitrate may not be stored with flammable or combustible materials; the 2021 Beirut Port explosion (2,750 tons of ammonium nitrate) and prior U.S. incidents reinforce why this section exists

  Part 126 is administered through the Coast Guard's Captain of the Port (COTP) authorities — the COTP for each major port zone oversees facility designations and permit issuance and may conduct inspections at any time. Facilities that lose their designation or operate without a required permit face civil penalties and potential port order restrictions prohibiting further cargo operations. The framework interacts with OSHA's Process Safety Management standard (29 CFR Part 1910.119) and EPA's Risk Management Program (40 CFR Part 68), which impose parallel safety planning requirements on facilities handling large quantities of highly hazardous chemicals — creating a multi-agency compliance environment for waterfront facilities handling the most dangerous cargo.

• 46 CFR Part 10 — Merchant Mariner Credential (43 sections across 4 subparts — the comprehensive framework governing issuance, renewal, medical certification, and training approval for all U.S. merchant mariners; the MMC is the single credential that every person serving on a U.S.-flag commercial vessel — from able seaman to master — must hold to work legally; authority: 46 U.S.C. §§ 7101–7126):

  • § 10.201 — General characteristics of the Merchant Mariner Credential: the MMC is a single combined document that replaced three previously separate instruments — the Merchant Mariner's Document (Z-card, for unlicensed mariners), the merchant marine license (for officers), and the STCW certificate (for international voyages); the MMC lists all endorsements the holder is qualified to carry and is issued by the Coast Guard's National Maritime Center (NMC)
  • § 10.203 — TWIC requirement: an applicant for an MMC must also hold a valid Transportation Worker Identification Credential (TWIC) — the TSA-issued biometric credential for maritime workers; failure to obtain or hold a valid TWIC is grounds to deny an MMC application; the TWIC/MMC coupling creates a unified security and credentialing system for all commercial mariners
  • § 10.205 — Validity: an MMC is valid for 5 years from date of issuance; the NMC may issue a temporary MMC pending completion of background checks; an MMC may be renewed up to 8 months before expiration without losing the original expiration cycle
  • § 10.209 — Application procedures: all applications are processed through the NMC (centralized in Martinsburg, WV) with the applicant appearing at a Regional Examination Center (REC) for identity verification, fingerprinting, and document submission; applications for original MMCs, renewals, raises of grade, and new endorsements all flow through the same process
  • § 10.211 — Criminal record review: the Coast Guard conducts mandatory criminal record checks for all MMC applicants; a felony conviction within the preceding 10 years for a drug offense, or a conviction at any time for certain violent crimes, disqualifies an applicant; the Coast Guard evaluates other criminal history using a multi-factor analysis considering nature of offense, time elapsed, and evidence of rehabilitation
  • § 10.213 — National Driver Register check: no original MMC or renewal with a new expiration date may be issued without checking the National Driver Register for driving-while-intoxicated convictions — because operating a vessel under the influence is a primary cause of maritime casualties; a DWI within 3 years can preclude issuance depending on circumstances
  • § 10.225 — Requirements for original MMC: an original applicant must demonstrate sea service hours appropriate to the requested endorsement (e.g., 360 days of qualifying sea service for an unlimited master's license), complete approved training courses, pass written examinations, hold a medical certificate, pass a drug test, and undergo the criminal and security review
  • § 10.227 — Renewal requirements: a renewal applicant must show 1 year of sea service in the preceding 5 years, or complete an approved refresher course in lieu of sea service; STCW revalidation requirements (international competency standards) must also be met; mariners who let their MMC lapse must requalify under original requirements
  • § 10.232 — Sea service documentation: sea service may be documented by certificates of discharge, pilotage service records, company letters, or logbook entries; the NMC evaluates sea service records and may credit partial service; STCW sea service on foreign-flag vessels counts if documented by the flag state
  • § 10.235 — Suspension and revocation: any MMC or endorsement may be suspended or revoked for violations of maritime law, drug or alcohol offenses, negligence, incompetence, or misconduct; suspension proceedings are brought before a USCG administrative law judge under 33 CFR Part 20; an emergency 45-day suspension without prior hearing is available when the Commandant finds the mariner poses an immediate threat to public safety
  • §§ 10.301–10.306 — Medical certificate requirements: a separate medical certificate is required for mariners holding officer endorsements or certain ratings; the medical exam must be performed by a physician and evaluate vision (correctable to 20/40 in one eye, with uncorrected 20/200 in the other acceptable for deck officers), hearing, color perception (no color blindness for deck officers who must distinguish navigation lights), and general health; medical waivers may be granted by the NMC where conditions are managed and do not impair safety
  • §§ 10.401–10.412 — Approved training courses: the NMC approves maritime training courses (firefighting, survival craft, medical first aid, radar, GMDSS, bridge resource management) offered by licensed schools and simulators; only NMC-approved courses satisfy training prerequisites for MMC endorsements; distance and e-learning courses are permitted with Coast Guard approval; simulators must meet international performance standards for the competencies they assess

  The MMC system reflects the 2010 International Convention on Standards of Training, Certification and Watchkeeping (STCW) Manila Amendments, which the U.S. implemented domestically through Part 10 and companion Parts 11 (officer qualifications), 12 (rating qualifications), and 15 (manning requirements). A merchant mariner's career trajectory — from ordinary seaman through able seaman, mate, and master — is tracked through successive MMC endorsements; each upgrade requires additional sea service, training, and examination. Approximately 180,000 MMCs are active at any time, covering the U.S. merchant marine fleet on domestic and international routes. Recent rulemakings: 89 FR 102332 (December 2024) — updated STCW endorsement requirements and medical certificate standards; 84 FR 30881 (June 2019) — streamlined application procedures and established online application submission through the Mariner Credentialing Program portal.

Pending Legislation

• HR 5666 (Rep. Van Drew, R-NJ) — Provides automatic short-term Coast Guard funding during appropriations gaps, covering operations up to 30 days. Status: Introduced.
• HR 6346 — Locks Coast Guard guidance on divisive symbols to Nov. 20, 2025 memorandum. Status: In Committee.

Recent Developments

The Coast Guard has been expanding its polar operations with the construction of new heavy icebreakers to maintain U.S. presence in the Arctic. Drug interdiction operations have shifted to counter increased drug trafficking via maritime routes. The Coast Guard Authorization Act has increased personnel end strength and authorized new cutters and aircraft. Recruitment and retention challenges have been an ongoing concern.

• In February 2026, the Coast Guard proposed to relocate the COLREGS demarcation line in New York Harbor and to establish two new fairway anchorages at Sabine Pass, Texas, improving navigation safety.
• In February 2026, the Coast Guard issued new base Great Lakes pilotage rates for the 2026 shipping season, resulting in an approximately 6 percent decrease in operating costs for Great Lakes shipping.

In January 2026, the Coast Guard established a temporary safety zone on the Rio Grande River near SpaceX's Boca Chica rocket test site to protect personnel, vessels, and the marine environment during launch operations.