He is considered a pioneer in the sport of canoeing and was involved in the British expedition of the first descent of the Dudh Kosi river.
Dave was born to Michael and Eve (née Levick) Manby in Johannesburg, South Africa where his father was the headmaster of the junior school at St John's College.
He also attended the University of Nottingham In 1976, at the age of 21, Dave was asked to join five other kayakers in a team of ten on the famous first descent of the Dudh Kosi, the river running off Mount Everest the trip leader was Mike Jones.
The whole expedition was filmed by Leo Dickinson and was shown on British prime time television in Boxing Day 1976.
Dave was involved in more first descent expeditions including the attempted 1978 K2 trip on the Braldu River (Pakistan) in which Mike Jones died while trying to save a companion.