Early in the afternoon one of the motor launches dropped a depth charge on an oil patch, and shortly afterwards one of the hydrophones picked up the sound of an internal combustion engine; a line of depth charges was run on the bearing indicated by the hydrophone.

The motor launches and the destroyer remained listening, until at about 6.0 P.M.a submarine came to the surface not far from Motor Launch No.

135, which fired two rounds at the submarine before the latter submerged.

Other motor launches closed in, and depth charges were dropped by them in close proximity to the wash of the submarine.

Oil came to the surface, and more depth charges were dropped in large numbers on the spot for the ensuing forty-eight hours.
Eventually objects came to the surface clearly indicating the presence of a submarine.