“Federal waters” does not have one universal legal boundary. The term can refer to offshore areas under particular federal authority, such as the U.S. territorial sea, the exclusive economic zone, or waters covered by a specific federal law. The boundary also varies by context: fishing rules, pollution controls, navigation, and offshore energy leasing may use different definitions. Knowing which law applies—and where its boundary lies—is essential before fishing, boating, building, or conducting business offshore.
What “Federal Waters” Means
In everyday conversation, federal waters usually means ocean waters beyond a state’s coastal jurisdiction. In law, however, it is a shorthand rather than a single, all-purpose category. Federal authority can apply in different ways across the same stretch of water, and states may retain authority close to shore even while federal laws also apply.
For example, the federal government has sovereignty over the territorial sea, while it has specific sovereign rights over resources in the U.S. exclusive economic zone (EEZ). Federal agencies may regulate navigation, fisheries, pollution, or energy development under separate statutes. Therefore, a place called “federal waters” for one purpose is not automatically treated the same way under every other law.
The practical question is not just whether water is federal, but which legal boundary and which federal law govern the activity.
The Main Offshore Boundaries
State coastal waters
Many federal and state laws distinguish between state waters and offshore waters. Along most of the U.S. coastline, the state’s seaward boundary is generally three nautical miles from the baseline used to measure the territorial sea. A nautical mile is slightly longer than a land mile: one nautical mile equals about 1.15 statute miles.
There are important exceptions. Texas and the Gulf Coast of Florida, for example, have state boundaries extending nine nautical miles offshore in specified areas. Some boundaries also involve historic claims or other legal details. The line should not be assumed to be a uniform distance from the visible beach; the official baseline and boundary are determined under applicable law and geographic rules.
State waters are not free from federal law. Federal navigation, environmental, and safety requirements may apply within state waters, while states can administer or enforce certain federal programs under approved arrangements. The distinction concerns the scope of jurisdiction, not whether federal law is present at all.
The U.S. territorial sea
The United States claims a territorial sea extending 12 nautical miles from its baseline. The baseline is generally the low-water line along the coast, subject to rules for bays, river mouths, and other geographic features. In this zone, the United States exercises sovereignty over the water, seabed, subsoil, and airspace, subject to international-law rights such as the right of innocent passage for foreign ships.
The territorial sea is not the same as the state boundary. In many places, state jurisdiction reaches about three nautical miles offshore, while the federal government’s territorial sea extends to 12 nautical miles. That means a coastal area can lie beyond state waters but still within the U.S. territorial sea.
The 12-nautical-mile limit is established by Presidential Proclamation 5928 and reflects the United States’ territorial-sea claim. It is a key boundary for sovereignty and many federal purposes, but it is not the outer limit of U.S. authority over offshore resources.
The contiguous zone
Beyond the territorial sea, the United States claims a contiguous zone extending up to 24 nautical miles from the baseline. This zone is not U.S. territory in the same sense as the territorial sea. Under international law and U.S. law, the country may exercise limited control there to prevent or punish certain violations relating to customs, fiscal matters, immigration, and sanitation.
The contiguous zone is therefore not a general extension of complete federal jurisdiction over every activity. Its legal purpose is narrower than the territorial sea’s. A person looking at a map should not interpret the 24-nautical-mile line as a single boundary for fishing, oil leasing, or all federal regulation.
The exclusive economic zone
The U.S. EEZ generally extends from the outer edge of the territorial sea to 200 nautical miles from the baseline, where geography allows. In the EEZ, the United States has sovereign rights to explore, exploit, conserve, and manage natural resources, including fish, oil, gas, and other resources in the water column, seabed, and subsoil.
The EEZ is not equivalent to national territory. Other countries retain freedoms of navigation and overflight, as well as other internationally lawful uses of the sea. The U.S. government’s authority in the EEZ is tied to the rights and jurisdiction recognized by domestic law and international law, rather than unlimited sovereignty over every activity.
Where the coasts of the United States and another country are less than 400 nautical miles apart, the EEZ boundary may be established by agreement or other applicable legal principles rather than extending 200 nautical miles from each coast. Maritime boundaries can also be affected by islands and international agreements.
Federal Waters for Fishing
For recreational and commercial fishing, “federal waters” commonly means ocean areas beyond the applicable state-water boundary, especially areas managed under federal fisheries laws. In much of the country, this often means waters more than three nautical miles offshore. In parts of the Gulf of Mexico, the state boundary is generally nine nautical miles, so the commonly used state-to-federal transition differs.
That shorthand does not mean every fishery is managed identically or that federal rules begin at precisely the same point for every species. The Magnuson-Stevens Fishery Conservation and Management Act provides the main framework for federal fishery management in the EEZ. Regional fishery management councils develop plans, and the National Marine Fisheries Service (NOAA Fisheries) implements regulations. State and federal agencies may coordinate management, and some species or fisheries have rules that cross jurisdictional lines.
Before fishing offshore, anglers should check the rules for the species, location, season, gear, and type of fishing. A federal permit or reporting requirement may apply, and state licenses may be required even when fishing beyond state waters. Regulations can also include catch limits, size limits, closures, restricted areas, and requirements for handling protected species.
Fishing location alone does not determine every requirement. A vessel’s registration, the species being targeted, and the specific fishery can affect which agency’s rules apply. NOAA Fisheries and the relevant state fish and wildlife agency are the best starting points for current requirements.
Federal Waters for Offshore Energy and Leasing
Offshore oil, gas, and renewable-energy activities are governed by federal laws and agency programs that use their own geographic and administrative boundaries. The Bureau of Ocean Energy Management (BOEM) oversees offshore energy planning and leasing on the federal Outer Continental Shelf (OCS). The OCS generally includes submerged lands seaward of state coastal waters, subject to statutory definitions and boundary exceptions.
The OCS is not simply another name for the entire EEZ. It refers to the seabed and subsoil under federal jurisdiction for specified purposes, while the EEZ describes a maritime zone and associated resource rights. Federal offshore energy leases are issued in designated areas and carry conditions, environmental reviews, and other requirements. A project may also need permits or approvals from other federal, state, or local authorities.
Federal waters can also host offshore wind projects. BOEM identifies and leases areas for potential development, but leasing does not by itself authorize construction or operation. Projects generally undergo further review and must secure required approvals. The precise location, seabed rights, and applicable environmental laws matter.
Federal Water Jurisdiction Is Different From Offshore Boundaries
Not every use of “federal waters” refers to the territorial sea or EEZ. Some federal statutes regulate particular waters based on their connection to interstate commerce, navigation, or other statutory criteria. For instance, the Clean Water Act regulates “navigable waters,” defined in the statute as “the waters of the United States,” but the scope of that term is a distinct legal question and has changed through legislation, regulations, and court decisions.
As a result, a river, lake, wetland, or coastal waterway may be subject to federal regulation even though it is far inland and nowhere near the ocean’s 12- or 200-nautical-mile boundaries. Conversely, identifying a location as part of the EEZ does not answer every question about whether a particular permit or environmental statute applies there.
Federal authority can also arise from laws governing ships, marine pollution, protected species, national defense, and maritime safety. The applicable statute, regulations, court decisions, and agency guidance determine the scope of authority in each case.
Quick Comparison of Offshore Zones
| Zone | General distance from baseline | What the boundary generally means |
|---|---|---|
| State coastal waters | Usually up to 3 nautical miles; certain Gulf areas extend to 9 | State jurisdiction over coastal waters, subject to applicable federal law |
| Territorial sea | Up to 12 nautical miles | U.S. sovereignty, subject to international-law limits such as innocent passage |
| Contiguous zone | Up to 24 nautical miles | Limited enforcement authority for specified customs, fiscal, immigration, and sanitation matters |
| Exclusive economic zone | Generally up to 200 nautical miles | U.S. sovereign rights and jurisdiction over specified natural resources and activities |
These distances are measured from the legally defined baseline, not necessarily from the shoreline point a person can see. The table is a general guide, not a substitute for official boundary data or legal advice.
How to Check Whether a Location Is Federal Waters
When the boundary matters for a real activity, it is safer to identify the exact coordinates and applicable law rather than rely on a general phrase. Several resources can help:
- For fishing: Check NOAA Fisheries, the relevant regional fishery management council, and the state agency responsible for licensing and regulations.
- For maritime boundaries: Consult NOAA nautical charts and official U.S. maritime boundary information. Charts are essential for navigation, but the legal status of a line should be confirmed through authoritative sources.
- For offshore energy: Review BOEM maps, lease information, and project documents for the relevant Outer Continental Shelf area.
- For pollution or construction permits: Contact the responsible federal agency, such as the Environmental Protection Agency or U.S. Army Corps of Engineers, and confirm whether state or tribal requirements also apply.
- For navigation and vessel safety: Review U.S. Coast Guard rules and current notices for the operating area.
Useful starting points include the National Oceanic and Atmospheric Administration, NOAA Fisheries, the Bureau of Ocean Energy Management, and the Magnuson-Stevens Act definitions in 16 U.S.C. § 1802. For the territorial-sea claim, see Presidential Proclamation 5928.
Common Misconceptions About Federal Waters
“Federal waters start exactly three miles offshore everywhere.”
That is not correct. Three nautical miles is a common state boundary, but specified Gulf Coast areas generally extend to nine nautical miles. The applicable line also depends on the legal baseline and boundary description.
“The EEZ is U.S. territory.”
The EEZ gives the United States important rights over natural resources and jurisdiction over specified matters, but it is not the same as the territorial sea. Other states retain recognized freedoms, including navigation and overflight.
“Federal waters have one set of rules.”
Rules vary by activity. A fishing closure, a navigation rule, an offshore lease, and a pollution permit may rely on different legal authorities and boundaries. Multiple federal agencies—and sometimes state agencies—can have roles in the same location.
“Federal waters are always beyond state waters.”
State and federal authority can overlap. Federal laws may apply in state waters, and state law may remain relevant to people and activities farther offshore. The correct answer depends on the statute, the subject, and the location.
In the United States, “federal waters” most often describes offshore areas where federal authority applies, but it does not identify one universal line. State boundaries, the 12-nautical-mile territorial sea, the 24-nautical-mile contiguous zone, and the EEZ extending generally to 200 nautical miles serve different legal purposes. For any specific activity, the governing agency and law—not the label alone—determine the rules.