[2] He was educated at George Watson's School before studying medicine at the University of Edinburgh, from where he graduated with an MB ChB and an MD in 1945.

Two years later, Watson moved to St Andrews University Department of Medicine under Sir Ian Hill,[2] working in Dundee hospitals.

Watson's early research was in the field of anticoagulant therapy but the tragic death of his young son from severe congenital heart disease, provided the impetus for him to undertake pioneering research work in congenital heart disease in children.

From this, Watson developed a diagnostic and treatment technique that involved the insertion of narrow tubes into the heart – cardiac catheterisation.

A car accident brought this outdoors lifestyle to an abrupt halt however, leaving Watson paralysed and in great pain.