Operated by B Flight, a training unit, at RAF Gosport. The "S" serial in this era stood for "Sea". It was for aircraft used by the Fleet Air Arm and aircraft used to train crews for the Fleet Air Arm. In the case of S1710, this was torpedo dropping. The FAA was administratively part of the RAF at the time. However aircraft assigned to ships came under Royal Navy command. In 1939 the entire FAA was put under navy control. Photo from: Imperial War Museums