Maritime law is that branch of law dealing with issues of ships, seamen, and shipping. It includes the law of navigation, admiralty, and commercial marine insurance. It is a broad field of law that includes matters such as the law of the sea, shipowners’ liability, collisions at sea, cargo damage, and pollution.

In the United States, federal courts and state courts have concurrent jurisdiction over most maritime cases. This allows parties to choose which court they want to hear their case and it ensures that federal maritime law is the law that applies, even when state procedural laws differ from those of the federal courts.

The first step towards codification was undertaken following the end of a series of armed conflicts, with the conferences held by the League of Nations codifying freedom of navigation (Barcelona Conference of 1921), maritime ports and the concept of merchant navies (Geneva Convention of 1923). The League of Nations was succeeded by the International Maritime Organisation which has taken further steps to codify the law of the sea.

It is now common practice for shipping companies to employ contract lawyers to negotiate the terms of charter agreements and to draw up transport contracts. These contracts are do ut facias contracts, meaning that they automatically apply to any voyage and that the carrier is obliged to carry persons or goods from one place to another. These contracts may contain a safe-berth clause. In Kossick v. United Fruit Co., 365 U.S. 731 (1961), it was held that an oral agreement between a seaman and a shipowner whereby the latter in consideration of the seaman’s forbearance to press his maritime right to maintenance and cure promised to assume the consequences of improper treatment of him at a Public Health Service hospital was enforceable as a maritime contract.