Keith Collin joined the Isleworth Penguins as a teenager and at the age of 15 won the inaugural National Boys Diving Championships when he was also third in the senior ASA Springboard Championship. Collin won the 1958 British Plain Diving Championship and went to that year´s British Empire and Commonwealth Games in Cardiff where he won the 3-metre springboard gold medal. After finishing 26th in the springboard event at the 1960 Roma Olympics he made a second Commonwealth Games appearances at Perth, Australia, in 1962 but failed to medal. He was, however, the British springboard champion the following year, after which he retired from competitive diving and continued his work in a London airline office. He briefly came out of retirement in 1967.