2. Admiralty Criminal Jurisdiction.—
The constitutional grant embraces criminal as well as civil cases and no crime can escape punishment because committed on shipboard or on the high seas. The provisions of the Constitution in regard to the trial of crimes under the laws of the United States require the proceedings to be according to the practice of the common law, so that they are before a jury as in ordinary cases and the ordinary rules of criminal law are applied. These crimes are covered by the Criminal Code (10 U. S. Comp St. 1916, 10419-10444; 10445-10462; 10463-10483). There may also be other crimes according to the law of the place where the vessel may be or according to the laws of the State or country from which she hails. Merchant vessels are regarded for many purposes as floating portions of the country to which they belong and of the particular State of their home port. An American merchant vessel on the high seas will therefore continue under the appropriate laws both of the United States and of her own particular State, and while in foreign ports she will also be subject to local law. She will never be outside the scope of some law and although several jurisdictions may overlap, crimes committed on board will not escape punishment.