This is a case from the US Supreme Court.
The United States was at war against Spain. The US Navy was ordered to enforce a blockade against Cuba – the isle then appertaining to Spain. A US warship seized two Cuban fishing vessels and took them to Key West. The ships were auctioned as prizes. The US Navy was also cognizant of the fact that the Cuban fishermen were seasoned mariners and likely to be pressed into Spanish naval service. This would then do the United States no bit of good.
The owners of the auctioned fishing vessels launched a law suit for the recovery of the monies generated from the same of their fishing smacks. They argyed that the seizre and subsequent sale were unlawful.
The US Supreme Court found that customary international law forbade the impounding of fishing boats. This dated to 1403 when Henry IV of England was at war against France. Both sides needed herring and to seize fishing boats of the other side would simply starve both peoples and not advance either cause. France and England signed a treaty vowing not to sequester fishing boats. This was honoured.
To seize these craft was against ius ad gentium – the law of peoples. The proceeds of the sale were returned to the proprietors together with damages. The captain of the US warship has misinterpreted the law.