Archaeology, Underwater

the investigation of ancient and medieval remains located in seas, rivers, and lakes. The remains include sunken ships as well as settlements or burial grounds that were inundated as a result of a changed shoreline, an earthquake, or some other natural phenomenon. Underwater archaeology originated in the early 20th century, and operations were carried out by divers working from special vessels. Beginning in the mid-20th century, underwater operations by archaeological specialists outfitted with lightweight diving equipment acquired increasing importance.