The problem was exacerbated by technological limitations; the Sea MARC sonar used by the expedition had a relatively low resolution and was a new and untested piece of equipment. It was nearly lost only 36 hours after it was first deployed when the tail was ripped off during a sharp turn, destroying the magnetometer, which would have been vital for detecting Titanic's hull. Nonetheless it managed to survey an area of some 500 square nautical miles (1,700 square kilometres) and identified 14 possible targets.[22] A documentary of this expedition, featuring Orson Welles, was titled Search for the Titanic (1981).[23]