A former European Tour pro, Cowen played in seven Opens and won the 1976 Zambia Open.
Aged 19, he sold his driver to Gary Player for $100 after out-hitting him with it by 40 yards.
In 2004, Cowen opened his own golf academy in Rotherham, Yorks.
Louis Oosthuizen, Lee Westwood and Henrik Stenson occupied the top three spots of the 2010 Open – when they were all coached by Cowen
He was named UK Coach of the Year at the 2010 UK Coaching Awards.
He has coached a dozen players to Major glory, including Harrington, Clarke and Willett.