It’s a distillation of several islands of the Hebrides – including Arran, which I’d count as the southernmost of the Inner Hebrides. I know exactly where it’s placed on my mental map of the Hebrides. Its closest neighbours are Coll and Tiree.
The village of Balvaig is a 
blend of many Island and west coast mainland viillages I’ve known over the years.
My late step-father (who was not only the most amazing man I’ve ever met, but also a blood relative – he was my grandmother’s first cousin; he and my mother didn’t marry until both were in advanced years) was a highly-regarded figure in the Scotch whisky distilling industry. He always maintained that a good blend is better than a poor single malt. So I like to think of Soma and Balvaig as being good blends!
Fiona Cameron: Contemporary Fiction 