Jurisdiction generally describes any authority over a certain area or certain persons. In the law, jurisdiction sometimes refers to a particular geographic area containing a defined legal authority. For example, the power of federal government spans the entire United States.  Each state is also a jurisdiction unto itself, with the power to pass its own laws.  Smaller geographic areas, such as counties and cities, are separate jurisdictions to the extent that they have powers that are independent of the federal and state governments.

Jurisdiction in admiralty is different from common law jurisdiction.  It governs maritime questions and offenses.  It has a strong international aspect, but may undergo independent changes in several countries.  Certain universal features exist in all countries that have admiralty law and such international features are given serious consideration by admiralty courts.

There are five types of cases which can only be brought in federal court: Limitation of Shipowner’s Liability, Vessel Arrests in Rem, Property arrests Quasi in Rem, Salvage cases, and Petitory and Possession Actions.  Besides these five types of cases, all other maritime cases, such as claims for personal injuries, cargo damage, collisions, maritime products liability, and recreational boating accidents may be brought in either federal or state court The common element of those cases are that they require the court to exercise jurisdiction over maritime property.

A state court hearing an admiralty or maritime case is required to apply the admiralty and maritime law, even if it conflicts with the law of the state, under a doctrine known as the “reverse-Erie doctrine.”  While the “Erie doctrine” requires that federal courts hearing state actions must apply substantive state law, the “reverse-Erie doctrine” requires state courts hearing admiralty cases to apply substantive federal admiralty law.  However, state courts are allowed to apply state procedural law.