Maritime law applies where two conditions are both met: the incident takes place on navigable waters of the United States, and it has a substantial connection to traditional maritime activity. So where does maritime law apply in practice? On the open ocean, the Great Lakes, major interstate rivers and the canals linking them, and sometimes on land or on fixed offshore structures when a vessel or federal statute pulls the situation into the maritime framework. A boating accident on a private landlocked lake usually isn’t covered. A car plunging off a bridge into a navigable river usually isn’t either. A collision between two commercial fishing boats on that same river almost certainly is.
What Counts as Navigable Waters
The Supreme Court set the standard in The Daniel Ball (1870): a waterway is navigable when it can serve as a highway for commerce between states or with foreign nations in its ordinary condition.1Legal Information Institute. The Daniel Ball, 77 U.S. 557 The test is capacity for interstate or international trade, not whether commerce is actually happening on the water at the moment.
Under that standard, the open ocean, the Great Lakes, major river systems like the Mississippi, and the canals that connect them all qualify.2eCFR. 33 CFR 329.4 – Navigable Waters of the United States A body of water entirely within one state and cut off from any interstate commercial route doesn’t. A private recreational lake with no outlet to an interstate waterway falls under state law no matter how large it is.
Why Location Alone Isn’t Enough
Being on navigable water is necessary, not sufficient. In Executive Jet Aviation v. City of Cleveland (1972), a plane crashed into Lake Erie, and the Court held there was no admiralty jurisdiction. The incident happened on navigable water, but it had nothing to do with maritime activity.
The Court refined the rule in Jerome B. Grubart, Inc. v. Great Lakes Dredge & Dock Co. (1995) into a two-part nexus test. An incident on navigable water also has to satisfy both of these:
- Disruptive potential: the incident could disrupt maritime commerce.
- Maritime character: the activity that caused the incident bears a substantial relationship to traditional maritime activity.
That’s why driving a car off a bridge into a river doesn’t trigger maritime law. The activity (driving) has no relationship to maritime commerce. Two commercial fishing boats colliding on the same river satisfy both prongs without difficulty. The character of the activity matters as much as the location.
When Maritime Law Reaches Onto Land
Jurisdiction doesn’t always stop at the water’s edge. The Admiralty Extension Act pulls injuries and property damage that occur on land into federal maritime jurisdiction, as long as a vessel on navigable water caused them.3Office of the Law Revision Counsel. 46 USC 30101 – Extension of Jurisdiction to Cases of Damage or Injury on Land A vessel’s wake damaging a dock, a crane on a barge striking a worker standing on a pier, or a ship spilling fuel that contaminates shoreline property can all qualify. The vessel on the water has to be the cause.
Separately, the Longshore and Harbor Workers’ Compensation Act covers certain maritime workers injured at land-side locations like piers, wharves, dry docks, and terminals. More on that below.
What Counts as a Vessel
Maritime law defines “vessel” broadly. Federal navigation rules sweep in nearly every type of watercraft, from container ships to air-cushion vehicles.4U.S. Coast Guard. Navigational Rules Ships, barges, tugs, cruise ships, fishing boats, and floating work platforms all qualify. The Coast Guard classifies personal watercraft like jet skis as Class A inboard motor vessels, subject to the same federal regulations as other powerboats in that category, and incidents involving them on navigable waters can fall within admiralty jurisdiction.
The vessel also has to be “in navigation.” A ship docked to load cargo still counts. A vessel hauled into dry dock for major overhaul or stripped and abandoned likely doesn’t. Courts sometimes call a permanently withdrawn vessel a “dead ship,” and once that label attaches, maritime jurisdiction over it ends. The question is whether the vessel remains practically capable of serving as transportation on water.
Permanently moored structures create gray areas. A floating casino bolted to shore, with engines removed, that never leaves its slip is far less likely to qualify than one that occasionally repositions under its own power. Courts look at whether the structure retains any transportation function.
Offshore Platforms on the Outer Continental Shelf
Oil and gas platforms sit on the seabed, not on the water, so they don’t fit the vessel-on-navigable-waters framework. The Outer Continental Shelf Lands Act fills the gap by extending federal law, including maritime law, to the subsoil and seabed of the outer continental shelf and to artificial islands, installations, and devices attached to the seabed for resource exploration or production.5Office of the Law Revision Counsel. 43 USC 1333 – Laws and Regulations Governing Lands A worker injured on a rig 80 miles offshore can invoke federal maritime protections even though the rig is a fixed structure.
Zones Out at Sea
International law divides the ocean into zones radiating outward from the coast, each with different rules about which nation has authority. The United Nations Convention on the Law of the Sea sets the framework:
- Territorial sea, 0 to 12 nautical miles: the coastal nation exercises full sovereignty, and its domestic laws apply. Foreign vessels retain a right of innocent passage.6United Nations Convention on the Law of the Sea. United Nations Convention on the Law of the Sea Part II
- Contiguous zone, 12 to 24 nautical miles: the coastal state can enforce its customs, immigration, and pollution laws, but doesn’t have full sovereignty.6United Nations Convention on the Law of the Sea. United Nations Convention on the Law of the Sea Part II
- Exclusive economic zone, up to 200 nautical miles: the coastal state controls exploration and exploitation of natural resources, including fishing, seabed mining, and energy production. Other nations keep freedom of navigation.7United Nations Convention on the Law of the Sea. United Nations Convention on the Law of the Sea Part V
- High seas, beyond the EEZ: no single nation has jurisdiction. Ships are governed by the laws of their flag state, the country where they’re registered. That’s why cruise lines often register vessels in places like the Bahamas, Panama, or Liberia.8United Nations Convention on the Law of the Sea. United Nations Convention on the Law of the Sea Part VII
Foreign government-owned vessels operating commercially can sometimes be sued in U.S. courts despite sovereign immunity. Federal law carves out an exception when a foreign state’s vessel is engaged in commercial activity with a direct effect in the United States and a maritime lien based on that activity is at stake.9Office of the Law Revision Counsel. 28 USC 1605 – General Exceptions to the Jurisdictional Immunity of a Foreign State
Who the Rules Protect, and Where
Maritime law treats people on and around the water differently depending on their role. The categories map onto where the person is and what they’re doing.
Crew members who qualify as “seamen” under the Jones Act can sue their employer for negligence, a right most land-based workers don’t have.10Office of the Law Revision Counsel. 46 USC 30104 – Personal Injury to or Death of Seamen Qualifying requires a substantial connection to a vessel or fleet in navigation: significant working time aboard and duties that contribute to the vessel’s mission.
Maritime workers who don’t qualify as seamen (longshoremen, ship repairers, shipbuilders, harbor workers) fall under the Longshore and Harbor Workers’ Compensation Act. Coverage requires a situs test (injury on navigable waters or an adjoining area like a pier, wharf, dry dock, or terminal) and a status test (work that’s an integral part of maritime employment, such as loading or unloading vessels).11GovInfo. 33 USC 903 – Coverage If a vessel’s negligence caused the injury, the worker can also bring a third-party claim against the vessel owner.12Office of the Law Revision Counsel. 33 USC 905 – Exclusiveness of Liability
Passengers on cruise ships and ferries are covered too, and can bring negligence claims for unsafe conditions aboard. Cruise ticket contracts routinely impose tight limits: notice requirements, short filing windows, and clauses designating a specific court. Those terms are routinely enforced.
When a death caused by negligence occurs on the high seas more than three nautical miles from U.S. shore, the Death on the High Seas Act is the exclusive remedy, and the recoverable damages are more limited than general maritime law allows closer to shore.13Office of the Law Revision Counsel. 46 USC 30302 – Cause of Action Where the death occurred can change the value of the claim.
Maritime law applies a pure comparative negligence rule: your own fault reduces your recovery but never eliminates it.14Office of the Law Revision Counsel. 46 USC 30304 – Contributory Negligence A plaintiff 40 percent at fault still recovers 60 percent of damages, which is more favorable than the rule in some states.
Which Courts Hear Maritime Cases
Federal district courts have original jurisdiction over admiralty and maritime cases.15Office of the Law Revision Counsel. 28 USC 1333 – Admiralty, Maritime and Prize Cases The same statute’s “saving to suitors” clause preserves the right to bring maritime claims in state court when common-law remedies are available. Jones Act negligence claims can go in either federal or state court, and the injured seaman chooses. In rem actions against the vessel itself are the main exception; those must be filed in federal court.
Choice of forum is a strategic decision. Federal courts apply uniform maritime law; state courts apply maritime law with procedural variations. Where you file can affect jury selection and how damages are calculated.
Deadlines to Watch
Maritime filing deadlines are shorter and less forgiving than many people assume. The general rule is three years from the date the cause of action arose for personal injury or death arising from a maritime tort.16Office of the Law Revision Counsel. 46 USC 30106 – Time Limit on Bringing Maritime Action for Personal Injury or Death Several common situations run shorter:
- Cruise ship injuries: ticket contracts frequently require written notice within six months and suit within one year. Courts routinely enforce these.
- Death on the High Seas Act: the personal representative has three years, limited to deaths beyond three nautical miles from shore.13Office of the Law Revision Counsel. 46 USC 30302 – Cause of Action
- Vessel owners seeking to limit liability: six months after receiving a written claim.17Office of the Law Revision Counsel. Federal Rules of Civil Procedure, Rule F – Limitation of Liability
The biggest mistake is assuming state personal injury deadlines apply. A cruise ticket contract can cut your window to a year, and if you don’t read the fine print, you won’t learn about it until the deadline has passed.