On 18 June 1928, Amundsen joined a rescue operation to save another competitor, the Italian aviator Umberto Nobile. Nobile had crashed his airship Italia on a return voyage from the North Pole, and he and his surviving crew members found themselves drifting helplessly on pack ice. Amundsen boarded a Latham 47 flying boat along with a team of French Air Force pilots to try to reach them.
McCallum and his team reckon the Latham 47 should have been about 19 nautical miles south of Bear Island when the plane's last radio message was picked up at 1845 on 18 June. Using an underwater robot, the equipment can get down to 20cm resolution on the sea bed. And it'll have to be precise as all that's probably left of the plywood-built plane is its engines.