The song was by (I think) Gavin Sutherland, who with his brother Ian formed The Sutherland Brothers (duhhh..) and Quiver.

Other notable songs were "The Arms of Mary", "The Dream Kid", "You Got Me Anyway"

I always hated Rod Stewart's cover of Sailing - the original version was stark, simple and evocative.. not lush, overorchestrated and self-indulgent. (in my opinion)

Cheers

Steven