Knowles represented the Bahamas in sailing at the 1960, 1964, 1968 and 1972 Olympics. In Tokyo, Knowles competed in the 5.5 class. In 1963, he became a Vice Commander of the new Bahamas Air-Sea Rescue Auxilliary (BASRA) organisation. Over the years, Knowles has continued to participate in competitive sport, taking part in
Masters swimming tournaments. In 2010, he competed at the US National Masters Swimming Championships where he won a bronze in the 100 yd breaststroke and, later that year, at the World Masters Championships in Sweden. In 2024, the 93 year old Knowles, his son
Andy Knowles, grandson
Jeremy Knowles, and 14 year-old grandson competed in the Bahamas National Swimming Championships in the 4 x 50 m team relay in an unprecedented "generations" team. == Personal life ==