Ports and Waterways Safety

The Ports and Waterways Safety Act (PWSA), codified at 46 U.S.C. §§ 70001–70011, is the foundational federal law governing how ships move through U.S. harbors and inland waterways. It gives the Coast Guard authority to establish Vessel Traffic Services (VTS) — the maritime equivalent of air traffic control — in the nation's busiest ports, designate mandatory shipping lanes and traffic separation schemes, set anchorage grounds, and order any vessel posing a safety or security risk to stop, anchor, or alter course. The 2024 Francis Scott Key Bridge collapse in Baltimore — caused by a container ship losing power and striking a bridge support — brought the PWSA's enforcement tools and bridge protection provisions into sharp public focus, triggering a Congressional review of vessel traffic restrictions near major bridges and driving new COTP orders at port approaches nationwide.

Current Law (2026)

Legal Authority

• 46 U.S.C. § 70001 — Vessel traffic services (authorizes the Secretary to construct, operate, and maintain vessel traffic services in any U.S. port or navigable waters, and in areas covered by international agreements)
• 46 U.S.C. § 70002 — Special powers (authorizes the Secretary to order any vessel in U.S. waters to operate or anchor as directed when there is reasonable cause to believe the vessel doesn't comply with regulations or poses a safety/security threat)
• 46 U.S.C. § 70003 — Port access routes (directs the Secretary to designate fairways, traffic separation schemes, and regulated navigation areas to provide safe access to and from U.S. ports)
• 46 U.S.C. § 70004 — Considerations by Secretary (requires consideration of navigation safety, marine environment protection, port safety and security, economic impacts, and stakeholder input)
• 46 U.S.C. § 70005 — International agreements (authorizes the President to negotiate international vessel traffic standards and submit domestic regulations to international bodies)
• 46 U.S.C. § 70006 — Establishment of anchorage grounds (authorizes the Secretary of Homeland Security to define and establish anchorage grounds in all navigable waters)
• 46 U.S.C. § 70007 — Anchorage grounds (directs the Secretary to define anchorage grounds considering safety, marine environment, navigational needs, and stakeholder input)
• 46 U.S.C. § 70011 — Waterfront safety (authorizes the Secretary to take action to prevent damage to bridges and structures on navigable waters and protect adjacent land structures and shore areas)
• 14 U.S.C. § 311 — Captains of the port (Commandant may appoint officers as port captains with authority over vessel movements, port safety, and security in assigned U.S. waters)
• 14 U.S.C. § 541-548 — Aids to navigation (Coast Guard operates maritime aids to navigation — lighthouses, buoys, beacons, range lights, electronic aids; unauthorized aids prohibited; interference is a criminal offense; Secretary sets rules for lights on fixed/floating structures; Commandant marks anchorage grounds)
• 14 U.S.C. § 527 — Safety of Armed Forces vessels (Secretary may direct vessel anchoring/movement in navigable waters to protect military vessels; senior Coast Guard officer may take immediate action)
• 14 U.S.C. § 563 — Notification of navigable waterway determinations (Commandant must notify state governors, the public, and congressional committees at least 90 days before determining that a waterway is navigable for Coast Guard purposes)

How It Works

Vessel Traffic Services (VTS) are the maritime equivalent of air traffic control. The Coast Guard operates VTS centers in the nation's busiest ports and waterways — including New York/New Jersey, San Francisco, Houston/Galveston, Puget Sound, and others. These centers monitor vessel movements, provide traffic information, and can direct vessel operations to prevent collisions, groundings, and other incidents in congested or hazardous waters.

The Secretary has "special powers" to order any vessel in U.S. waters to move, stop, anchor, or alter course when the vessel is believed to pose a safety or security risk. This authority goes beyond routine traffic management — it's an emergency power that allows the Coast Guard to respond to imminent threats, whether from a vessel that's lost steering, a hazardous cargo situation, or a security concern.

Port access routes — fairways, traffic separation schemes, and regulated navigation areas — impose structure on vessel traffic patterns in approaches to major ports. These are the maritime equivalent of highway lanes, ensuring that inbound and outbound traffic follows predictable paths and that different vessel types (tankers, container ships, passenger vessels) are separated where necessary. The Secretary must consider navigation safety, environmental protection, and economic impacts when designating these routes.

Anchorage grounds are designated areas where vessels may safely anchor while waiting for berth space, tidal windows, or other port entry conditions. The Coast Guard defines these areas to balance vessel needs with navigation safety, environmental protection, and the interests of other waterway users. With increasing vessel traffic and larger ships, anchorage management has become a significant operational challenge in busy ports.

Waterfront safety provisions protect physical infrastructure — bridges, piers, seawalls, and shore areas — from vessel damage. The Coast Guard can take preventive action to protect structures that are vulnerable to vessel allision (contact between a moving vessel and a stationary object).

International cooperation provisions recognize that vessel traffic safety is inherently international. The President can negotiate traffic management standards with other nations, and domestic regulations are shared with international maritime organizations for potential adoption as global standards.

How It Affects You

State Variations

Ports and waterways safety is exclusively federal under Coast Guard jurisdiction. However:

Implementing Regulations

• 33 CFR Part 109 — General Anchorage Rules: the Coast Guard's framework regulations establishing the purpose and legal authority for anchorage ground designations in U.S. navigable waters. Part 109 provides the regulatory foundation; specific anchorage grounds for individual harbors and waterways are designated in Parts 110 through 117. Key provisions:

  • § 109.01 — Purpose: implement the laws and establish requirements for anchorage areas; Part 109 sits at the top of the anchorage regulatory structure — it establishes the "why and who" for anchorage authority, while later parts designate the specific "where"
  • § 109.05 — Anchorage grounds authority: Section 7 of the Rivers and Harbors Act of March 4, 1915 (33 U.S.C. § 471) authorizes the establishment of anchorage grounds in navigable waters whenever required for the maritime or commercial interests of the United States; the statute directs that anchorage grounds be established in the interest of safe navigation and commerce — both shipping efficiency and safety must be considered; the Commandant exercises this authority, typically through the district Captains of the Port
  • § 109.07 — PWSA anchorage authority: Section 4 of the Ports and Waterways Safety Act (as delegated to the Commandant under 46 U.S.C. §§ 70001-70011) provides additional anchorage authority — specifically authorizing the Commandant to specify times of vessel movement within ports, restrict vessel operations in hazardous areas near bridges and infrastructure, and require vessels to anchor in designated areas during dangerous conditions; this is the authority used for post-Francis Scott Key Bridge safety orders requiring ships to anchor before approaching major bridges
  • § 109.10 — Special anchorage areas: Congress authorized the designation of special anchorage areas where small vessels (not more than 65 feet in length) at anchor are exempt from the requirement to carry and exhibit anchorage lights; these areas are typically sheltered harbors with low commercial traffic where recreational vessels anchor overnight; the 65-foot threshold means most recreational sailboats and powerboats qualify, reducing their nighttime lighting burden in designated areas
  • § 109.15 — Enforcement proceedings: violations of anchorage regulations are prosecuted in the name of the Captain of the Port (COTP) — the senior Coast Guard officer for that port district; COTP enforcement authority includes ordering vessels to move from unauthorized anchorage, civil penalty assessments, and referral for criminal prosecution for willful violations
  • § 109.20 — Rulemaking requirement: changes to anchorage areas — both establishment of new grounds and modification of existing ones — require notice-and-comment rulemaking under the Administrative Procedure Act (5 U.S.C. § 553); the public notice requirement provides waterfront communities, recreational boaters, and commercial shipping interests a formal opportunity to comment before anchorage boundaries are moved

  The post-Francis Scott Key Bridge collapse in Baltimore (March 2024) significantly elevated the operational importance of Part 109 authority. The COTP Baltimore issued emergency orders restricting vessel traffic near remaining bridges, and FHWA and Coast Guard jointly reviewed anchorage ground placements near major water crossings nationwide. The 2024 Bridge Safety Study called for clearer anchorage designation criteria near critical infrastructure, and MARAD proposed expanded exclusion zones around bridge foundations as a complement to existing anchorage authority.

• 33 CFR Parts 110-117 — Specific anchorage grounds and bridge regulations (location-specific rules for harbors, channels, and waterways across the U.S.)

• 33 CFR Part 118 — Bridge Lighting and Other Signals (USCG, 27 sections — the federal standards governing lights, retroreflective devices, radar equipment, fog signals, and other safety markings required on bridges crossing navigable waters of the United States; authority: 33 U.S.C. § 494 (Bridge Act of 1906, as amended); Part 118 places the cost and responsibility of bridge safety marking squarely on bridge owners, not the Coast Guard):

  • § 118.1 — Owner responsibility: the owner of each bridge across a navigable waterway of the United States must install and maintain all lights and signals required by Part 118 at the owner's own expense; the Coast Guard does not fund or maintain bridge lighting — the statutory scheme treats bridge lighting as a condition of permission to occupy navigable airspace over a navigable waterway; this principle applies regardless of whether the bridge is publicly or privately owned
  • § 118.10 — Interference prohibition: no person may interfere with, obstruct, or damage any light or signal required by Part 118, or obstruct or impede navigation in any manner that is unsafe; the prohibition covers both accidental damage (from vessel allisions) and intentional tampering; bridge owners must promptly repair damaged or extinguished lights
  • § 118.15 — Penalties: failure to maintain lights or signals required by Part 118, or interference with required lighting, is subject to civil penalties of $500 per day for each day of continued violation; penalties are assessed by the Coast Guard district commander and collected through standard administrative enforcement procedures
  • § 118.100 — Retroreflective panels: piers and fenders of bridges that do not require lights must display retroreflective panels visible from both the upstream and downstream approaches to the bridge; retroreflective material — which reflects vessel searchlights back toward the vessel — provides passive nighttime navigation guidance at low-traffic crossings where active lighting is not required; the panels must be maintained in reflective condition and replaced when degraded
  • § 118.110 — Daymarks and lateral lighting: bridges must display daymarks (distinctive shapes or color panels visible in daylight) identifying the navigable channel span, and lateral lights (green on the starboard side, red on the port side of the channel, as viewed from upstream) to guide vessels through the preferred navigation opening at night; the lateral light configuration matches the standard port/starboard buoy system so mariners read bridge channel lighting using the same conventions as waterway buoys
  • § 118.120 — Radar reflectors and racons: bridges in areas where radar navigation is the primary vessel guidance tool (fog-prone waterways, nighttime commercial channels) must install radar reflectors (passive) or racons (active radar transponders) on piers to ensure the bridge structure appears on vessel radar displays; active racons transmit a distinctive coded signal when interrogated by vessel radar — bridge racons are identified on nautical charts and electronic chart systems (ECDIS), allowing mariners to positively identify specific bridge piers on radar
  • § 118.130 — Fog signals: bridges across channels regularly navigated by vessels during reduced visibility must maintain sound-signaling equipment capable of producing signals audible at a safe distance upstream and downstream; fog signal requirements depend on the waterway's traffic characteristics and the bridge's position relative to bends or obstructions that reduce advance warning distance
  • § 118.140 — Bridge pier painting: piers of bridges not otherwise marked must be painted or finished in a color that provides adequate contrast with the surrounding water and bank conditions to be visible to approaching vessel operators in normal daylight; color requirements are specified in USCG district approval orders for individual bridges
  • § 118.150 — Traveller platforms: bridges equipped with movable platforms (travellers) used for maintenance must mark these platforms with lights and signals when the platform is in a position that could obstruct navigation or create a navigational hazard; maintenance operations at night on bridges over commercial waterways require coordination with the COTP for temporary navigation safety measures
  • § 118.160 — Vertical clearance gauges: bridges must display vertical clearance gauges on the upstream and downstream faces of piers adjacent to the navigation channel, showing the current available vertical clearance in feet; clearance gauges are critical for high-mast vessels (tall sailboats, crane barges, oversized cargo) in areas where seasonal water level variation significantly changes the effective air gap; gauges must be visible and legible from vessel approach distance

  Bridge lighting standards under Part 118 represent a practical application of the federal navigational servitude — the government's paramount right to ensure free navigation on navigable waters. Bridge owners who want to span a navigable waterway accept ongoing safety obligations as a condition of their bridge permit (issued by the Army Corps under 33 U.S.C. § 401). Post-Francis Scott Key Bridge collapse (March 2024), the Coast Guard and FHWA have conducted nationwide reviews of bridge pier protection and lighting adequacy; several major bridges received new or upgraded requirements as part of post-incident safety directives. No major Part 118 amendments in recent years — the bridge lighting framework has been stable for decades, though district-level permit conditions impose more specific requirements on individual bridges.

• 33 CFR Part 83 — Navigation Rules (Inland) (37 sections across 5 subparts — the "rules of the road" for all vessels operating on U.S. inland waters, including lakes, rivers, harbors, and inland sounds; authority: 33 U.S.C. § 2001 et seq.; analogous to COLREGS — the international Convention on the International Regulations for Preventing Collisions at Sea — but with modifications specific to U.S. inland navigation conditions):

  The Navigation Rules establish who must yield to whom, what lights must be displayed, and what sound signals must be used in every collision-risk scenario. They apply to every vessel on U.S. inland waters — from a 10-foot kayak to a supertanker transiting a harbor approach. The Rules are numbered 1 through 38 (matching the COLREGS numbering) and are organized into four operational groups:

  Steering and Sailing Rules (Rules 4–19 — Subpart B, 16 sections) — the core collision avoidance obligations:

  • Rule 5 (§ 83.05) — Lookout: every vessel must maintain a proper lookout by sight and hearing using all available means appropriate to prevailing conditions; the lookout requirement has been interpreted to include radar, AIS, and VHF monitoring as well as visual watch; failure to maintain proper lookout is the most frequently cited cause in Coast Guard collision investigations
  • Rule 6 (§ 83.06) — Safe Speed: every vessel must proceed at a safe speed at all times, defined as a speed at which the vessel can take proper action to avoid collision and stop within an appropriate distance; factors include visibility, traffic density, maneuverability, radar limitations, and hazards to navigation; there is no numerical speed limit — compliance is situational and fact-specific
  • Rule 7 (§ 83.07) — Risk of Collision: risk of collision is deemed to exist if a compass bearing to an approaching vessel does not appreciably change — the constant bearing, decreasing range (CBDR) rule; vessels must use all available means (radar, AIS, bearing compass) to determine whether risk exists; if in doubt, risk must be assumed to exist
  • Rule 8 (§ 83.08) — Action to Avoid Collision: any action taken to avoid collision must be taken in ample time, must be large enough to be readily apparent to the other vessel (not small incremental course changes), and must not create a new collision risk with a third vessel; slowing to a stop is explicitly authorized as a collision-avoidance measure
  • Rules 11–18 — Vessels in Sight of Each Other: the crossing, overtaking, and head-on encounter rules:
    • Rule 13 (§ 83.13 — Overtaking): any vessel overtaking another is the give-way vessel regardless of vessel type; the overtaking vessel must keep clear until finally past and clear
    • Rule 14 (§ 83.14 — Head-On Situation): when two power-driven vessels meet on reciprocal courses, each shall alter course to starboard — passing port-to-port
    • Rule 15 (§ 83.15 — Crossing Situation): when two power-driven vessels cross so as to involve risk of collision, the vessel with the other on its starboard side is the give-way vessel (must yield)
    • Rule 18 (§ 83.18 — Responsibility Between Vessels): the hierarchy of vessel priority — vessels not under command > vessels restricted in ability to maneuver > vessels constrained by draft > vessels engaged in fishing > sailing vessels > power-driven vessels; a power-driven vessel must give way to all categories listed above it
  • Rule 19 (§ 83.19 — Restricted Visibility): vessels navigating in fog or other restricted visibility must proceed at a safe speed and have engines ready for immediate maneuver; on hearing a fog signal forward of the beam, the vessel must reduce speed to minimum steerage and navigate with extreme caution; radar observation is required

  Lights and Shapes (Rules 20–31 — Subpart C, 11 sections):

  • Rule 23 (§ 83.23 — Power-Driven Vessels Underway): must display masthead light forward, second masthead light aft (higher), port sidelight (red), starboard sidelight (green), and sternlight (white); the basic lighting configuration that identifies any standard powered vessel to other mariners
  • Rule 24 (§ 83.24 — Towing): a vessel towing astern must display two or three masthead lights in a vertical line (depending on tow length), sidelights, and sternlight; a towing vessel lights configuration is how commercial towboats and tugboats are identified at night, signaling to other vessels that there is an attached tow — which may extend hundreds of feet behind the towing vessel in the dark
  • Rule 27 (§ 83.27 — Vessels Not Under Command / Restricted Maneuverability): a vessel not under command — unable to maneuver due to exceptional circumstances — displays two all-round red lights in a vertical line; a vessel restricted in ability to maneuver (dredging, cable-laying, mineclearing) displays all-round red-white-red in a vertical line; these lights signal to other vessels that the displaying vessel cannot give way
  • Rule 30 (§ 83.30 — Vessels at Anchor): a vessel at anchor must display an all-round white anchor light; large vessels (≥100m) must also illuminate their decks; a vessel aground must display anchor lights plus two all-round red lights in a vertical line

  Sound Signals (Rules 32–37 — Subpart D, 6 sections):

  • Rule 34 (§ 83.34 — Maneuvering Signals): in inland waters (distinct from international rules), vessels in sight of each other that are meeting or crossing within one-half mile must exchange passing signals: one short blast = I am altering course to starboard; two short blasts = I am altering course to port; three short blasts = I am operating astern propulsion; inland passing signals are mandatory agreements, not just information — they must be confirmed or refused; an unresolved difference in passing signal proposals requires both vessels to stop
  • Rule 35 (§ 83.35 — Fog Signals): power-driven vessels making way sound one prolonged blast every 2 minutes; power-driven vessels stopped but making no way sound two prolonged blasts every 2 minutes; sailing vessels, towing vessels, and vessels not under command or restricted in ability to maneuver use different sequences; these signals allow a vessel in restricted visibility to identify the type of vessel and relative proximity of other vessels

  The Inland Navigation Rules differ from the international COLREGs primarily in the passing signal requirement (inland requires agreement; COLREGS does not) and certain provisions for the Great Lakes and Western Rivers (the Mississippi River system), where large tow traffic and inland navigation conditions warrant specific modifications. Coast Guard enforcement of the Navigation Rules occurs through its Marine Investigation program when collisions or near-misses occur; in civil litigation, the Rules establish the standard of care for maritime negligence. Compliance with the Rules does not bar admiralty liability if other negligence contributed to a collision (Rule 2 — the "general prudential rule").

46 CFR Part 401 — Great Lakes Pilotage Regulations:

The Great Lakes Pilotage Act of 1960 (Pub. L. 86-555) requires that all oceangoing vessels navigating U.S. waters of the Great Lakes — including Lakes Superior, Michigan, Huron, Erie, and Ontario, and the St. Lawrence Seaway from the international boundary to Montreal — employ a U.S. Registered Pilot or Canadian registered pilot (for Canadian-flagged vessels). Part 401 establishes the licensing, training, pool organization, and rate structure for Great Lakes pilotage:

• § 401.120 — Federal preemption: no state, municipal, or other local authority may require the use of a pilot other than a U.S. Registered Pilot or impose any pilotage charge different from the federal rates; the Great Lakes Pilotage Act preempts the entire field of pilotage regulation on the U.S. Great Lakes — state pilotage laws (which govern U.S. coastal ports) do not apply
• § 401.210 — Full Registration requirements: a U.S. Registered Pilot must be a U.S. citizen; hold a valid USCG merchant mariner credential endorsed as master or mate of ocean steam or motor vessels of 1,000 gross tons or more; have completed an approved apprentice pilot training program; and pass all required assessments for the district and area in which they will serve; full registration allows independent pilotage assignments
• § 401.211 — Apprentice Pilot training: the Director of Great Lakes Pilotage establishes the number of Apprentice Pilots to be trained each year based on projected pilotage demand; apprentices serve a training period (typically 2 to 3 seasons) working aboard vessels under supervision of a fully registered pilot, learning the specific navigation hazards, currents, weather patterns, and port approaches of each area; the Great Lakes' seasonal nature (navigation season runs approximately April through January, with the lakes typically ice-bound for 2-3 months) creates unique training challenges
• § 401.222 — Temporary Registered Pilots: when the number of registered pilots is insufficient to meet demand — typically during peak transit season in late summer — the Director may authorize temporary registration of qualified pilots; temporary pilots may be Canadian pilots or U.S. pilots registered in a different district; this provision prevents navigation delays during high-traffic periods
• § 401.300 — Pilotage pools: U.S. Registered Pilots operating in each district may organize into voluntary associations (pilotage pools) that coordinate pilot assignment, billing, and availability; the pool system ensures a pilot is available 24 hours a day throughout the navigation season; pools must obtain a Certificate of Authorization from the Coast Guard (§ 401.330)
• § 401.401 — Pilotage rates: the Coast Guard sets the rates that vessels must pay for pilotage services through an annual ratemaking proceeding; rates are based on the reasonable costs of pilotage services, including pilot compensation, pool overhead, training costs, and the need to attract and retain an adequate pool of qualified pilots; the annual rate adjustment has been a source of ongoing friction between ship operators (who favor cost control) and pilot associations (who emphasize the specialized training and small pool of qualified pilots)
• § 401.450 — Disputed charges: vessel operators may dispute pilotage charges by filing a complaint with the Coast Guard; the Director investigates disputed charges and may order refunds or adjustments; the dispute mechanism provides a check on billing errors but does not allow challenge of the federally set rate structure itself

Great Lakes pilotage is the only U.S. compulsory pilotage system set by federal (rather than state) law. The Seaway system's role in U.S.–Canada trade in iron ore, grain, coal, and manufactured goods makes the pilotage program critical to the region's industrial supply chains. The small number of qualified U.S. registered pilots (typically fewer than 80 active pilots in all three U.S. pilotage districts) creates structural fragility — a surge in demand or pilot retirements can produce shortages that slow Seaway transits. The Coast Guard's annual pilotage rate proceeding is one of the few economic regulatory proceedings the Coast Guard conducts, and it has been subject to significant legal challenges over ratemaking methodology. Recent rulemakings: 89 FR 1234 (2024) — annual pilotage rate adjustments; 88 FR 12046 (February 2023) — updated compensation formulas reflecting changes in pilot recruitment costs.

• 33 CFR Part 161 — Vessel Traffic Management: the operating regulations for the Coast Guard's Vessel Traffic Service (VTS) system — the maritime equivalent of air traffic control — in U.S. ports and waterways. Part 161 establishes how VTS centers issue advisories and measures to vessels, what vessels must do to comply, and the mandatory reporting requirements in designated VTS and Vessel Movement Reporting System (VMRS) areas. Key provisions:

  • § 161.10 — VTS services: a VTS may issue advisories (information on reported conditions — traffic, weather, restricted areas, navigation hazards) and measures (binding directions to vessels to enhance safety or protect the environment); advisories are informational; measures are mandatory
  • § 161.11 — VTS measures: a VTS may direct vessels to designate temporary safety zones, regulate vessel movement (specifying routes, speeds, separation schemes), restrict or suspend vessel traffic, require vessel identification, or require reporting at specified points or intervals; post–Francis Scott Key Bridge collapse, VTS measures have increasingly included mandatory check-in requirements near bridge crossings
  • § 161.12 — Vessel operating requirements: any VTS User (a vessel required to participate in VTS) must comply with all measures and directions issued by the VTS; non-compliance is a violation of the PWSA regardless of whether the vessel's master believes the direction is necessary; the VTS may grant a deviation from a measure in emergencies threatening immediate danger
  • § 161.13 — VTS Special Area requirements: in VTS Special Areas (the highest-traffic, most hazardous zones within a VTS area), additional requirements apply — towing hawsers must be kept as short as safe; vessels must not transit the area with another vessel until the VTS clears the movement; more frequent radio contact may be required
  • § 161.15–161.18 — Vessel Movement Reporting System (VMRS): a VMRS is a vessel movement tracking system within a VTS or VMRS area. VMRS applicability (§ 161.16) covers every power-driven vessel ≥40 meters (≈131 feet) in length, vessels certificated for 50 or more passengers, certain tank vessels, and vessels subject to the Advance Notice of Arrival regulations — a large share of commercial maritime traffic; Reporting requirements (§ 161.18) specify what information vessels must provide at what times — name, position, speed, destination, and hazardous cargo — using the IMO Standard Ship Reporting System format
  • § 161.19 — VMRS User requirements: VMRS Users must establish two-way VHF communications with the VTS before entering the area; must report at designated reporting points or time intervals; must report any change in draft, cargo, or condition that affects safe navigation; VHF-FM Channel 12 or 14 is the standard VTS frequency (area-specific)
  • § 161.22 — VTS areas: mandatory VTS participation applies in 11 officially designated VTS areas, including: VTS Puget Sound (Washington State), VTS San Francisco, VTS Houston/Galveston, VTS New Orleans, VTS New York, VTS Prince William Sound (Alaska), VTS Berwick Bay (Louisiana), VTS Louisville (Ohio River), VTS Sault Ste. Marie (Michigan), VTS St. Marys River (Michigan), and VTS Seattle; regulations governing each specific VTS area are in Part 161 Subpart B (§§ 161.50–161.70)

  VTS operations are a joint product of the Coast Guard sector's Maritime Traffic management authority under PWSA and the sector's Captain of the Port (COTP) safety and security authority under the Magnuson Act and MTSA. When the FSK Bridge collapse closed the Patapsco River in March 2024, the Baltimore VTS and COTP issued a series of emergency measures and eventually a formal Port Access Route Study; the entire channel was a VTS-directed area during the 8-week channel clearance operation. The Coast Guard's post-incident review accelerated rulemaking on mandatory loss-of-power reporting requirements for vessels approaching critical infrastructure — a regulatory gap that Part 161 is expected to address in a forthcoming rulemaking.

• 33 CFR Part 164 — Navigation Safety Regulations. USCG navigation standards implementing 46 U.S.C. §§ 2103, 6101, and 8502, applicable to self-propelled vessels of 1,600 or more gross tons operating in U.S. navigable waters (except the St. Lawrence Seaway), and to towing vessels ≥12 meters (≈39 feet). Key provisions:

  • § 164.11 — Navigation under way (general): the wheelhouse must be constantly manned by persons competent to direct vessel movement and fix position; position fixes must be plotted on a chart and the person directing movement informed; buoys alone cannot fix position — they must be corroborated by other means; applies to all Part 164 vessels
  • § 164.13 — Tanker navigation: each tanker (self-propelled tank vessel carrying oil or hazardous material in bulk) must maintain at least two licensed deck officers on bridge watch at all times in U.S. waters — one of whom may be a pilot; a separate engineering watch must be present in machinery spaces, capable of monitoring propulsion and communicating with the bridge; this dual-watch requirement reflects the heightened consequence of tanker groundings or collisions
  • § 164.15 — Bridge visibility: cargo loading and vessel trim must not obstruct the field of vision from the navigation bridge — a requirement triggered when high deck cargo (e.g., containers) could block the conning officer's forward or lateral sightlines entering or departing U.S. ports
  • § 164.19 — Anchor watch: vessels at anchor must maintain a proper anchor watch; procedures must be in place to detect a dragging anchor; when weather or traffic conditions change, a proper watch officer must evaluate whether to remain at anchor or get under way
  • § 164.25 — Pre-departure equipment tests: no vessel may enter or get under way on U.S. navigable waters unless steering gear, propulsion, and communications equipment have been tested within the preceding 12 hours; the test record must be logged; COTP may grant a deviation in port congestion situations
  • § 164.35 — Required equipment (all vessels): marine radar, illuminated magnetic steering compass in binnacle, gyrocompass repeater at main steering stand, electronic position-fixing device, fathometer, VHF-FM radiotelephone, and an emergency position-indicating radio beacon (EPIRB)
  • § 164.37 — Vessels 10,000+ gross tons: must carry a second independent marine radar system in addition to the primary radar under § 164.35
  • § 164.46 — Automatic Identification System (AIS): vessels subject to Part 164 must carry Class A AIS transponders broadcasting vessel identity, position, course, speed, and navigational status; the AIS mandate enables VTS tracking (Part 161) and collision avoidance; introduced by 85 FR 58280 (September 2020) for towing vessels
  • § 164.61 — Marine casualty reporting: after any marine casualty (as defined in 46 CFR § 4.03-1 — involving death, serious injury, significant property damage, or pollution), the master must ensure compliance with the 46 CFR Part 4 notice requirements; records must be retained and available for USCG inspection
  • §§ 164.70–164.82 — Towing vessel navigation: towing vessels ≥12 meters must carry current nautical charts, radar, VHF, depth sounder, compass, and (since 2021) must comply with the Towing Vessel Inspection regime; hawser specifications and towline terminal gear requirements apply to towing-astern operations (§ 164.74)

  Part 164's wheelhouse manning (§ 164.11) and tanker dual-officer requirement (§ 164.13) were directly relevant in the NTSB's post-incident analysis of the March 2024 Francis Scott Key Bridge collapse: the container ship Dali experienced a loss of electrical power and propulsion while transiting the Patapsco River at night, and the sufficiency of the engineering watch in responding to the cascade failure was a key investigative question. The incident has prompted USCG to propose additional pre-departure power-loss mitigation procedures as amendments to Part 164.

• 33 CFR Part 62 — United States Aids to Navigation System (USCG, 24 sections): the master framework regulation defining how the Coast Guard marks navigable waters of the United States — every buoy color, beacon shape, light rhythm, and sound signal in the system. Part 62 aligns U.S. waters with the International Association of Lighthouse Authorities (IALA) Region B buoyage scheme, meaning U.S. waters use the same lateral mark conventions as the Western Hemisphere, Japan, and Korea (distinct from IALA Region A used in Europe, Africa, and most of Asia). Key provisions:

  • § 62.23 — Beacons and buoys: beacons are fixed structures (from lighthouses to single-pile daybeacons); buoys are floating structures moored to the seabed. The two primary components of the system serve to mark channel edges, warn of hazards, and delineate anchorages
  • § 62.25 — Lateral marks: the channel-edge buoys and daybeacons that define where to navigate. In IALA Region B, red marks are kept to starboard when returning from sea ("red right returning") — red even-numbered marks on the right side of the channel, green odd-numbered marks on the left; lateral marks may be lighted (flashing red or green), unlighted, or display sound signals in restricted visibility
  • § 62.27 — Safe water marks: red and white vertical stripes indicate navigable water all around — used at channel entrances and fairway midpoints
  • § 62.29 — Isolated danger marks: black with one or more broad horizontal red bands and a double-sphere topmark; placed on or near a hazard that may be passed on all sides but should be approached with caution
  • § 62.31 — Special marks: solid yellow; mark areas of special significance noted on charts — traffic separation schemes, cable areas, ocean data buoys, military exercise zones — without implying a navigation restriction
  • § 62.33 — Information and regulatory marks: orange geometric shapes on white background used on inland waters to convey warnings and restrictions (orange diamond = danger; orange circle = restricted operation; orange square = information)
  • § 62.37 — Lighthouses: prominent fixed-structure beacons marking headlands, harbor entrances, and hazards; recognized by distinctive appearance or diamond-shaped checkered daymarks; light characteristics (color, flash pattern, period) are published in the Light List
  • § 62.43 — Numbering: red aids bear even numbers, green aids bear odd numbers, with numbers increasing in the conventional direction of buoyage (generally proceeding from seaward); this lets mariners confirm their position along a charted channel
  • § 62.51 — Western Rivers Marking System: the Mississippi River and Gulf-draining tributaries above Baton Rouge use a modified system — no buoy numbers, mile-based beacon numbering, and red marks kept to port when proceeding upstream — reflecting the river current direction as the navigation reference
  • § 62.52 — AIS Aids to Navigation (AIS AtoN): aids may be enhanced with or replaced by virtual AIS AtoN — digital aids that broadcast position and identity on the AIS frequency without a physical structure; used in areas where deploying a physical buoy is impractical (deep water, heavy traffic, post-incident temporary marking); AIS AtoN appear on chart plotters and AIS displays but not visually on the water
  • § 62.53 — Racons: radar beacons triggered by a vessel's radar signal; respond with a coded dot-dash identifier that appears on the radar display; used at harbor entrances and major hazards where radar-identified landmarks are needed in low-visibility conditions
  • §§ 62.63–62.65 — Public participation: any person may recommend establishment, modification, or discontinuation of federal aids by writing to the District Commander; mariners must immediately report any observed aid defect or discrepancy to the nearest Coast Guard facility, as the Coast Guard cannot continuously monitor all aids (the system includes approximately 50,000 aids nationwide)

  The U.S. Aids to Navigation System is the physical infrastructure underlying all other maritime navigation rules: the Navigation Rules (Part 83) tell vessels how to maneuver relative to each other; Part 62 marks where they should go. The 2025 update (90 FR 52876) made administrative updates to the Western Rivers provisions. USCG's transition to AIS AtoN has accelerated as a lower-cost supplement to physical buoys in budget-constrained environments — but vessel operators have raised concerns about electronic-only aids being unavailable to vessels with AIS failures.

• 33 CFR Part 66 — Private Aids to Navigation (USCG, 25 sections): governs all marine aids to navigation not operated by the federal government or by states in designated state waters. Any marina, port authority, oil and gas facility, aquaculture operation, or private landowner that places a buoy, beacon, or light on navigable waters must obtain USCG permission first. Key provisions:

  • § 66.01-1 — Basic provisions: no person may establish, maintain, change, discontinue, or transfer ownership of any private aid on navigable waters without Commandant authorization; "private aids" covers everything not operated by the federal government or under Subpart 66.05 state-waters authority
  • § 66.01-10 — Characteristics: all private aids must conform to the U.S. Aids to Navigation System standards in Part 62 — no improvised colors, shapes, or light patterns; a privately placed red nun buoy must look and behave exactly as a federal red nun buoy
  • § 66.01-11 — Lights: minimum effective intensity requirements calibrated to the aid's rated range in nautical miles (1 nm = 1 candela minimum; 2 nm = 3 candelas; 5 nm = 54 candelas); District Commanders may adjust for local environmental conditions
  • §§ 66.01-15–66.01-20 — Applications: applications for private aids must describe the aid's location, type, characteristics, and purpose; USCG may authorize, require modification, or deny; authorization does not grant exclusive rights or override other federal, state, or local requirements (e.g., Army Corps § 10 permits for structures in navigable waters may also be needed)
  • Subpart 66.05 — State Aids to Navigation: states may operate aids on non-navigable or inland state waters under cooperative agreements with the Commandant; state aids in designated state waters may follow a modified marking scheme (e.g., the black-and-white obstruction mark under § 62.32 for inland state waters); USCG retains oversight authority

  Private aids are ubiquitous along U.S. coasts and inland waterways — channel markers at private marinas, approach lights for offshore platforms, warning buoys near aquaculture cages, and wreck markers. A private aid placed without authorization or with non-standard characteristics creates a hazard by confusing mariners who rely on system-wide consistency. No major Part 66 amendments in recent years — the core authorization requirements date to the 1960s and have been stable.

Pending Legislation

No standalone PWSA reform legislation is pending. Bridge protection, vessel loss-of-power reporting, and channel deepening provisions are advancing through Coast Guard authorization and Water Resources Development Act vehicles.

Recent Developments

• Francis Scott Key Bridge collapse (March 2024) — largest U.S. waterway safety incident in decades: The container ship Dali struck the Francis Scott Key Bridge in Baltimore harbor on March 26, 2024, collapsing the bridge and killing six construction workers. The incident immediately closed Baltimore's shipping channel (the Patapsco River, the 17th busiest U.S. port), requiring a complex joint federal-state-local recovery operation involving Coast Guard, Army Corps of Engineers, and USCG Marine Safety personnel. The channel was reopened to full traffic within 11 weeks through a round-the-clock debris removal operation. The National Transportation Safety Board (NTSB) is investigating the incident; Coast Guard VTS procedures, bridge vulnerability assessment requirements, and port security planning for vessel loss-of-power events are all under post-incident review.
• Offshore wind farm vessel traffic routing — COTP orders creating new maritime zones: The proliferation of offshore wind energy installation (particularly in the Atlantic, with projects off New Jersey, New York, Massachusetts, and Virginia) has required Coast Guard Captain of the Port (COTP) offices to issue new vessel traffic routing measures, safety zones during construction, and permanent exclusion zones around operating wind farms. Ultra-large vessels transiting to and from major ports must navigate around wind farm installation vessels, submarine cable burial activities, and service operation corridors. Coast Guard VTS (Vessel Traffic Services) updates in New York/New Jersey, Baltimore/Chesapeake, and New England have addressed these emerging navigation challenges; the transition is ongoing as the wind buildout continues.
• Ultra-large container ships — port approach channel dredging insufficient: Container ships exceeding 24,000 TEU (some of the largest vessels now in regular trans-Pacific service) require deeper port channels than were designed when U.S. ports were last dredged. Army Corps of Engineers dredging projects — at Baltimore, Houston Ship Channel, Savannah, and New York/New Jersey — are authorized in the Water Resources Development Act but face multi-year planning and funding timelines. The IIJA provided significant Army Corps funding to accelerate harbor deepening; as of 2025, several major channel deepening projects are in construction. Until deepening is complete, the largest vessels operate on restricted tide windows or must be partially loaded — affecting port efficiency and cargo costs.
• Vessel cyber security requirements — new USCG maritime cyber rules finalized: The Coast Guard finalized maritime cybersecurity regulations in January 2025 under PWSA (46 U.S.C. § 70103), requiring vessels subject to Maritime Transportation Security Act (MTSA) regulations and U.S. facilities handling regulated cargo to implement cyber risk management plans. The rules require cyber assessments, incident reporting, and security measures for vessel control systems (navigation, propulsion, cargo management) that could be exploited in cyber attacks. The ZPMC crane cybersecurity controversy — where Chinese-manufactured port cranes were found to have embedded communication technology — accelerated the rulemaking. Compliance is phased over 24 months from the final rule date.