Sources

Caol Bhrannain: Fraser, Place-names of Arran
An Caol(as) Strandanach [From Captain MacFarlane SS Davaar between L Ranza & Gourock 7.5.10]: Watson CW9
Caolas Chille Branndain: Robertson MS371
An Caolas Branndanach: Robertson MS406, 4v

‘Kilbrennan Sound was given to me in Arran as an Caol Sradanach, probably a corruption of an Caolas Brandanach; here Kil- therefore is for caol, a strait, but the explanation of the latter part is obscure’.: Watson 1926, 274