Graham McDonald dived from 1940s to 1970s and he used the camera to record his diving experiences. He was invited to film the dedication of an underwater plaque in memory of the late P.M. Harold HoltEarly camera with handmade underwater casing, Invitation to commemoration of plaque to Harold Holt placed underwater.Underwater video camera in handmade aluminium waterproof casing Circa 1968. Copy of invitation to Harold Holt Commemoration plaque underwater placement off, on - on top of camera casecamera, underwater camera, camera casing, harold holt, comemoration