There are very few admiralty lawyers who are "piracy experts." Here's a better summary than I could do at the moment (from http://legal-dictionary.thefreedictionary.com/Piracy
The Constitution addresses piracy in Article 1, Section 8. It gives Congress "the Power … To define and punish Piracies and Felonies committed on the high Seas, and Offenses against the Law of Nations." Generally, the definition of pirates meant rogue operators at sea—independent criminals who hijacked ships, stole their cargo, or committed violence against their crew. But standards in all areas under the law changed in response to judicial rulings and to historical incidents, forming by the mid-1800s what became the basis for contemporary law.
In 1790 Congress enacted the first substantive antipiracy law, a broad ban on murder and Robbery at sea that carried the death penalty. In 1818, however, the U.S. Supreme Court ruled that the law was limited to crimes involving U.S. citizens: U.S. jurisdiction did not cover foreigners whose piracy targeted other foreigners (United States v. Palmer, 16 U.S. [3 Wheat.] 610). A year later, in 1819, Congress responded by passing an antipiracy law to extend U.S. jurisdiction over pirates of all nationalities.
By the mid-nineteenth century, two other important changes occurred. Penalties for certain piracy crimes—revolt and mutiny—were reduced and were no longer punishable by death. Then the Mexican War of 1846–48 brought a radical extension of the definition of a pirate. The traditional definition of an independent criminal was broadened to include sailors acting on commissions from foreign nations, if and when their commissions violated U.S. treaties with their government. The Piracy Act of 1847, which established this broader definition, marked the last major change in U.S. piracy law.
Today, the primary source of antipiracy law is title 18, chapter 81, of the United States Code, although numerous other antipiracy provisions are scattered throughout the code. Additionally, international cooperation has shaped a unique form of jurisdictional agreement among nations. Significant in bringing about this cooperation was the geneva convention on the High Seas of April 29, 1958 and the 1982 United Nations Convention on the Law of the Sea. The primary effect of such agreements is to allow pirates to be apprehended on the high seas—meaning outside of territorial limits—by the authorities of any nation and punished under its own law. This standard is unique because nations are generally forbidden by International Law from interfering with the vessels of another nation on the high seas. It arose because piracy itself has never vanished; in fact, since the 1970s, it has appeared to have undergone a resurgence.