MARITIME LAW | PERSONAL INJURY | ADMIRALTY JURISDICTION | FEDERAL MARITIME LAW
An explanation of the two-part locus and nexus test used to determine whether an injury case falls under federal admiralty jurisdiction and maritime law.
Published: August 20, 2026
Subject: Admiralty jurisdiction, locus and nexus requirements, and the Admiralty Extension Act
Primary Legal Authority: Jerome B. Grubart, Inc. v. Great Lakes Dredge & Dock Co., 513 U.S. 527 (1995)
Jurisdiction: Federal Admiralty and Maritime Law
Is My Injury a “Maritime” Case? Understanding Admiralty Jurisdiction
Not every accident that involves water is a “maritime” case. Whether federal maritime law applies to an injury — rather than ordinary state tort law — depends on a two-part test that courts have refined over decades. Because maritime law comes with its own rules on deadlines, damages, and procedure, the threshold question of jurisdiction can shape everything that follows.
The Two Requirements: Locus and Nexus
For a tort (injury) claim to fall within admiralty jurisdiction, the plaintiff must generally establish two things:
- Locus (location): the tort occurred on navigable waters; and
- Nexus (connection): the incident bears a substantial relationship to traditional maritime activity.
The first requirement, maritime locus, is satisfied by showing that the wrong occurred on navigable waters.
What “Nexus” Means Today
The Supreme Court developed the nexus requirement to focus admiralty jurisdiction on genuine maritime interests. Under modern doctrine, establishing nexus requires showing two elements:
- That the incident has a potentially disruptive impact on maritime commerce, and
- That the general character of the activity giving rise to the incident shows a substantial relationship to traditional maritime activity.
This formulation emerged from four key Supreme Court cases. First, the Court excluded admiralty jurisdiction over an airplane that crashed into a lake. Because the crash was fortuitously connected to navigable waters, it lacked a maritime connection.
Later decisions extended admiralty jurisdiction to pleasure boat collisions and docked vessel fires. These rulings confirmed that vessels do not need to engage in commercial trade or be underway for maritime law to apply.
The Admiralty Extension Act: When Harm Reaches Land
There’s also an important wrinkle for injuries that begin on the water but cause harm on land. The Admiralty Extension Act gives federal courts admiralty jurisdiction over torts committed by vessels on navigable waters even though the injury or damage is sustained on land. It was enacted in part to address “allisions” — situations where a vessel strikes a fixed object like a bridge. Crucially, to invoke this jurisdiction, the injury must emanate from a vessel on navigable waters, and the party invoking it must show vessel negligence (which can include tortious conduct of the crew on board that results in injury on land).
Why This Threshold Question Matters
Whether your case is “maritime” affects:
- Which law applies — federal maritime law versus state tort law;
- Deadlines — maritime torts carry their own limitation rules;
- Procedure and jury rights — including whether a jury trial is available and where the case can be heard.
Because these consequences are significant, the jurisdictional analysis is often one of the first things a maritime attorney evaluates.
What This Means If You Were Injured on or Near the Water
If you were hurt on a vessel, in the water, or by a vessel, your claim may be governed by maritime law — with rules quite different from an ordinary injury case. Rather than guess, have a maritime attorney assess whether your facts satisfy the locus and nexus requirements (or fall under the Admiralty Extension Act), because that determination drives the strategy for your entire claim.
Disclaimer: This blog post is provided for educational and informational purposes only. It is not legal advice and does not create an attorney-client relationship. Maritime law is complex and continues to evolve; the authorities discussed here are drawn from a general legal treatise and may have been modified by later court decisions or legislation. Do not rely on this article as a statement of the current law or as advice about your specific situation. For advice about your own case, consult a licensed maritime attorney.
Authorities Discussed in This Article:
- Jerome B. Grubart, Inc. v. Great Lakes Dredge & Dock Co., 513 U.S. 527 (1995)
- Executive Jet Aviation, Inc. v. City of Cleveland, 409 U.S. 249 (1972)
- Foremost Insurance Co. v. Richardson, 457 U.S. 668 (1982)
- Sisson v. Ruby, 497 U.S. 358 (1990)
- Admiralty Extension Act, 46 U.S.C. § 30101
About Maderal Byrne & Furst: Maderal Byrne & Furst PLLC is a Miami-based law firm that represents passengers seriously injured in cruise ship and maritime accidents. We encourage you to learn more about our firm, meet our attorneys, explore our other practice areas, review our results or see our rating and reviews on Google.
If you suffered an injury on or near the water, contact us for a free, confidential case evaluation. Because maritime claims carry strict deadlines, please reach out promptly.
