Duck boats, replicas of World War II-era amphibious vehicles, and a popular tourist attraction, make their way along the Charles River between Boston and Cambridge, Mass., Sunday, July 22, 2018. Five years after 17 people died when a tourist vessel known as a duck boat sank on a Missouri lake, the U.S. Coast Guard on Monday, Sept. 11, 2023 issued new rules for amphibious World War II vessels retrofitted for tourists. (AP Photo/Steven Senne, File)