Island I Vow (Elanvow in the fourteenth century) is situated at the northern end of Loch Lomond. A survey of Loch Lomond in 1701 refers to it as Ilan a Bou or the Booth Isle. This would suggest the Gaelic form as Eilean a’ Bhùtha ‘the island of the shop or booth’.
There are however a number of submerged rocks very close to this island well-known for being dangerous to sailors on the loch. It is therefore possible the original form of the island was Eilean a’ Bhogha ‘the island of the submerged rock’.
The odd modern form of the name is based on folk-etymology: a fanciful story claims that the name is derived from the Chief of Clan MacFarlane building a castle here and making a solemn ‘vow’ that he would allow no more clansmen hostile to him to pass down the loch.
For more information visit Ainmean-Àite na h-Alba