My first contact with him came 30-odd years ago when I was working briefly as a fisherman on the Hebridean island of Skye and had managed to buy one of the last commercial fishing boats that had been used purely under oar power. It was 18ft of rot held together with tar and cost me 200.
At the time I had never met Sir Iain, but had heard that there was this rich young man who was putting money into Gaelic projects and rang him on spec.
He immediately asked for the phone number of the call box and then phoned me back to spend about half-an-hour pouring out a paean of praise for my ridiculous endeavours, eventually suggesting that we use the boat, which he had never seen, as the centre-piece for a museum of Hebridean boats which, as he put it, would shake the world.
When I eventually put the receiver down, I left the phone box feeling 2ft taller, thrilled by his approbation and determined to serve the cause of Hebridean boats for all my days.
It was only later that I realised he had offered me nothing at all.
Thirty years later, it was hard to relate that man at the end of the line to the old Etonian whom I saw make an exhausted waitress hang around for two hours after her shift had finished so that she could sing a Gaelic song to his party of six guests.
But Iain was primarily a creative and such men are not like others. He was a somewhat confused individual who wrestled with his need to be both a laird and also a member, as he put it, of the exclusive brethren of the Gaels.
I was once rowing with Iain in a replica birlinn, the Aileach, and asked him if it wasn't a bit absurd for us to be spending our time trying to revive the Gaelic culture when, theoretically, the numbers suggested that the cause of saving it was already impossible.
"If you are visiting a dying man in hospital," he replied, "you don't say 'goodbye', you say 'keep fighting', and sometimes miracles happen."
If nothing else, Iain kept fighting and brought about more miracles than any of those who are often so keen to dismiss him for his many unusual peccadillos.
A stone to his cairn, he remains one of my heroes.