In the United States v. Benz case of 1930, the Supreme Court ruled that U.S. labor laws did not apply to foreign ships in American waters if applying those laws would interfere with the internal economy and discipline of the ship. The case arose when a German vessel, S.S. Crefeld, docked in Philadelphia for repairs and its crew demanded higher wages as per U.S law while working on these repairs. When their demand was refused by Captain Benz, they went on strike which led to their arrest under an old federal statute prohibiting seamen from deserting vessels needing repair work done in US ports. The court held that although Congress had power over foreign vessels within territorial limits of US harbors under international law; it could only exercise this power without infringing upon rights reserved by other nations through principles of comity (mutual respect between countries). Therefore, since application of wage provisions would intrude into internal affairs and management structure aboard a foreign ship - something traditionally left to jurisdiction where ship is registered - it was deemed inappropriate for such enforcement here.

In the dissenting opinion for United States v. Benz, Justice Stone argued that the majority's interpretation of the Prohibition Act was too narrow and inconsistent with its purpose. He contended that Congress intended to prohibit all importation of intoxicating liquors into the U.S., regardless of whether they were destined for personal use or resale. The majority's decision allowed an exception for liquor imported by seamen as part of their sea stores, which he believed contradicted this intent. Furthermore, he disagreed with their view that a ship in port is not within U.S territory; instead arguing it should be considered so under international law principles and past court decisions. Thus, any alcohol on board would be subject to prohibition laws once docked at a U.S port.