Naval air cadets.
M/S of cadet diving into river at royal naval station, he inflates dinghy in the water. M/S of cadets watching. M/S of officer explaining. Various shots of others diving in and paddling in dinghies.
M/S as they walk up to Firefly aeroplane, pilot gives them instructions. Various shots of the cadets, one gets in as passenger. C/U as propellor turns. M/S as three cadets look skyward. M/S of aircraft in flight.