Conservators working on the gunboat Philadelphia at the Smithsonian National Museum of American History in recent years took to marking with colored discs spots on the floor where the ship was shedding flakes from its wood structure.
The floor is covered with those markers, Jennifer Jones, curator of the Philadelphia, said during a presentation Thursday at the Lake Champlain Maritime Museum’s fifth annual virtual archaeology conference.
The ship, America’s oldest surviving warship, was raised from Lake Champlain’s Valcour strait by Lorenzo Hagglund in 1935 and has been on permanent display at the Smithsonian history museum in Washington since the museum’s construction in the early-1960s. It sank during the heat of battle on Oct. 11, 1776, when a scrappy fleet of American ships mustered its best defenses against British naval forces attempting to control the critical water corridor…