 He had also won the 1982 ASA National Championship title in the 200 metres backstroke.A founder member of Kelly College Swim Squad in Tavistock (along with Sharron Davies) Jameson represented Great Britain at the 1984 Summer Olympics in Los Angeles, where he finished 5th place in the 100-metre butterfly.He then won silver in the 100-metre butterfly at the 1985 European Championships (Sofia), behind the German star swimmer Michael Gross.