The Almeida de Carvalho was a research vessel that was built to sail among floating ice. Between 1972 and 2002 it was also used as a hydrographic ship of the Portuguese Navy. These ships collect information for the production of nautical charts. Yet de Almeida mainly conducted research missions. Originally the Almeide Carvalho was part of the US Navy under the name Kellar. The ship was sunk off the coast of Portimao in Portugal on September 21, as part of the Ocean Revival Project.