USCG Regulated Navigation Areas, Safety Zones, and Security Zones

33 CFR Part 165 is the U.S. Coast Guard's framework for controlling vessel access to portions of U.S. navigable waters. It authorizes Coast Guard District Commanders and Captains of the Port (COTPs) to establish regulated navigation areas, safety zones, security zones, and restricted waterfront areas — and permanently designates hundreds of specific geographic restrictions through Subpart F, covering everything from nuclear power plant waterways to LNG terminal approaches to naval base perimeters. If your vessel is approaching a zone marked on nautical charts as restricted, this regulation governs whether you need permission to enter and how to request it.

Current Rule (2026)

What This Rule Does

33 CFR Part 165 is the U.S. Coast Guard's framework for controlling vessel access to portions of U.S. navigable waters. It creates four distinct types of geographic restrictions — regulated navigation areas, safety zones, security zones, and restricted waterfront areas — and authorizes District Commanders and Captains of the Port (COTPs) to establish, modify, and enforce them. The Part also permanently designates hundreds of specific geographic zones through Subpart F, from nuclear power plant waterways to LNG terminal approaches to naval bases.

The central authority figure is the Captain of the Port (COTP), a designated Coast Guard officer responsible for a defined port zone. COTPs can establish temporary or permanent restrictions in their zone and are the primary point of contact for mariners seeking permission to enter restricted areas. District Commanders oversee COTPs and can issue broader regulations for entire USCG districts.

Zone Types and Their Legal Frameworks

Regulated Navigation Areas (RNA) (§§ 165.10–165.13, Subpart B): An RNA is a water area within a defined boundary where the Coast Guard has established specific vessel operating requirements — speed limits, exclusion of certain vessel classes, mandatory speed reduction zones, or vessel traffic separation schemes. RNAs respond to hazardous conditions such as shallow channels, congested waterways, or areas with underwater hazards. The COTP or District Commander may specify permitted entry times, vessel size limits, speed limits, or required equipment (§ 165.11). The master of any vessel in an RNA must operate in compliance with the RNA regulations; no person may authorize operation contrary to these rules (§ 165.13).

Safety Zones (§§ 165.20–165.23, Subpart C): A safety zone is a water area, shore area, or water-and-shore area to which access is limited for safety or environmental purposes. It may be stationary (fixed geographic limits) or mobile (a zone that moves with a vessel). Common safety zone applications include fireworks displays, regatta courses, construction operations, shipwrecks or disabled vessels, and environmental hazard events. Unless the establishing regulation provides otherwise: no person may enter a safety zone without COTP or District Commander authorization; no vessel, vehicle, or object may be brought into the zone without authorization; and no person may remain in a zone after being ordered to leave (§ 165.23).

Security Zones (§§ 165.30–165.33, Subpart D): A security zone is an area of land, water, or land and water designated to prevent damage or injury to vessels or waterfront facilities, to safeguard ports, harbors, U.S. territories, or waterways, or to secure observance of U.S. rights and obligations (§ 165.30). Security zones are the most restrictive zone type — no person or vessel may enter or remain in a security zone without the COTP's permission (§ 165.33). The COTP may board and search vessels that appear to threaten security within the zone. Security zones are commonly established around LNG carrier transits, nuclear power plant waterways, military vessel movements, and presidential or high-value visitor movements by water.

Naval Vessel Protection Zones (Subpart G, §§ 165.2010–165.2030): A naval vessel protection zone is a 500-yard perimeter established automatically around any U.S. naval vessel in the navigable waters of the United States (§ 165.2015). Unlike other zones, the naval vessel protection zone moves with the vessel. The Navy and Coast Guard share enforcement authority — in immediate-threat situations where Coast Guard officers are not present, the senior naval officer in command may take enforcement action (§ 165.2020). No vessel may approach within the 500-yard zone without permission from the naval vessel commander or COTP. Violations can result in use of force.

How Zones Are Established

Zones may be established on the initiative of any authorized Coast Guard official or upon request from any person (§ 165.5). Requests must generally be submitted at least 90 days in advance for non-emergency actions. Coast Guard notification of new or modified zones occurs through marine broadcasts, Local Notices to Mariners, local news media, leaflet distribution, and on-scene notice (§ 165.7). Emergency zones can be established immediately through oral notice.

Subpart F of Part 165 contains the permanent geographic catalog of established zones — over 320 individually numbered sections, each defining the exact coordinates, effective dates, and specific regulations for a specific location or recurring event. Subpart F entries cover everything from the LNG carrier safety zone for Boston Harbor (§ 165.110) to security zones for naval bases at San Diego (§§ 165.1101–1108) to recurring fireworks and airshow safety zones across every USCG district.

Key Provisions

• § 165.1 — Purpose: prescribes procedures and general regulations for RNA, safety zones, security zones, and restricted waterfront areas; lists specific areas in Subpart F
• § 165.5 — Establishment procedures: any person may request a zone; 90-day advance request typical; emergency authority allows immediate action
• § 165.7 — Notification: marine broadcasts, Local Notice to Mariners, local media; emergency zones by on-scene notice
• § 165.10 — RNA definition: a water area within a defined boundary for which specific vessel operating regulations have been established
• § 165.11 — Vessel operating requirements in RNAs: COTP may set entry times, vessel size limits, speed limits, traffic lane requirements, equipment mandates
• § 165.20 — Safety zone definition: limited-access area for safety or environmental purposes; may be stationary or moving
• § 165.23 — Safety zone general regulations: no entry without authorization; no vessels, vehicles, or objects without authorization; comply with COTP orders
• § 165.30 — Security zone definition: area designated to prevent damage to vessels or facilities, safeguard ports, or secure U.S. rights
• § 165.33 — Security zone general regulations: no entry without COTP permission; full compliance with COTP direction; Coast Guard may board and inspect vessels
• § 165.2015 — Naval vessel protection zone: 500-yard perimeter around U.S. naval vessels; moves with the vessel
• § 165.2020 — Enforcement authority: Coast Guard and senior naval officer share authority; force authorized in immediate-threat situations

How It Affects You

If you operate a recreational vessel: You may encounter safety zones established for events such as fireworks displays, marine races, and air shows — these are typically temporary and announced in advance through Local Notices to Mariners and radio broadcasts. You may also encounter permanent security zones around nuclear power plants, LNG terminals, and military facilities. Crossing into any zone without authorization is a federal violation. Monitor USCG broadcasts and check Local Notices to Mariners before transiting unfamiliar waterways.

If you operate a commercial vessel: You must comply with all RNA regulations in your operating area, including speed limits, lane designations, and equipment requirements. Commercial vessels seeking to transit security zones for legitimate business (port entry, fuel bunkering) must obtain advance COTP permission. LNG carriers and other hazardous cargo vessels typically have specific zone designations establishing protective bubbles during transit.

If you operate near naval installations: The 500-yard naval vessel protection zone applies wherever naval vessels navigate U.S. waters. Approaching within 500 yards of a naval vessel without authorization is prohibited; closer than 100 yards requires radio contact with the naval vessel. These rules apply to all types of vessels including recreational boats.

If you want to organize a waterway event (regatta, waterfront festival, fireworks): You must apply to your local COTP for a safety zone at least 90 days before the event. The COTP will review the request, coordinate with other users of the waterway, and issue or deny a temporary zone designation. The zone establishment is published in the Federal Register as a final rule.

If you believe a waterway zone is improperly established or overly broad: Persons may submit written requests for modification or removal of a zone to the applicable COTP or District Commander. Legal challenges to zone designations as Administrative Procedure Act rulemakings are also possible in federal district court.

Statutory Authority

This rule implements:

• 46 U.S.C. § 70034 — Port and waterway safety: authorizes the Secretary of the department in which the Coast Guard is operating to control vessel traffic through regulations establishing safety zones, security zones, regulated navigation areas, and other restrictions

Recent Rulemakings

No major structural amendments to the framework sections of Part 165 in recent years. Subpart F is continuously amended by individual zone establishment rules published in the Federal Register — hundreds of temporary and permanent zone actions occur annually, covering new LNG terminals, naval base expansions, major waterway events, and environmental hazard responses.

Recent Developments

• LNG export terminal security zones: The expansion of LNG export terminals along the Gulf Coast and Atlantic seaboard has driven establishment of permanent safety and security zones around these facilities under Part 165. LNG facilities present significant hazards — both from fire and explosion risk and from their status as potential terrorism targets. USCG coordinates with FERC, PHMSA, and the facility operators to establish appropriate safety zones for LNG vessel transits to export terminals.
• Offshore wind safety zones: BOEM-authorized offshore wind construction and maintenance activities have required USCG to establish safety and navigation zones around offshore wind farms during installation, cable laying, and operation. These zones protect construction workers and vessels from collision hazards while managing impacts on commercial fishing and other maritime users of the area. The Trump administration's 2025 offshore wind pause affected the pipeline of new zone establishment for planned wind projects.
• Presidential protection and security zones: USCG establishes waterway security zones for presidential movements and major national security events — including visits to waterfront properties, naval base events, and large public gatherings near navigable waters. The frequency of security zone actions increases during periods of elevated threat or when the President travels to waterfront locations.
• Post-hurricane and emergency zone management: Major hurricanes affecting Gulf Coast and Atlantic ports require USCG to establish Port Condition Whiskey, X-Ray, Yankee, and Zulu restrictions and safety zones for post-storm debris, sunken vessels, and damaged infrastructure. USCG's Captain of the Port uses Part 165 Subpart F authority to manage vessel traffic during and after storm events. Hurricane response zone management has become more complex as offshore energy infrastructure has grown.

Pending Action

No broad rulemaking of Part 165 is currently pending — zone establishment is inherently project-specific and handled through individual direct final rules or temporary rules. The Trump administration's 2025 offshore wind pause will reduce the volume of new construction safety zone rulemaking in 2025–2026; any resumption of offshore wind permitting will generate new safety zone rulemaking activity. LNG export terminal expansion — a Trump administration priority — will generate additional security zone rulemakings for new terminal construction and vessel transit routes. Maritime operators in areas with proposed offshore energy development (LNG terminals, offshore wind) should monitor Federal Register dockets for Part 165 proposed rules affecting navigation in their operating areas.