Tarbet Isle  'The island of the drag boat or portage place'
A VERY small wooded island, with large pine trees and often inhabited with large colonies of gulls, Tarbet takes its name from the nearby village and the isthmus on which it stands. Here the ocean in the shape of Loch Long makes its nearest approach to Loch Lomond, so that the pass from Arrochar to Tarbet made a natural approach for people from the sea wishing access to the land locked Loch. Several other places in Scotland on similar isthmus locations have acquired the same name, notably Tarbert in Argyll, Tarbert on Isle of Gigha, Tarbert on Harris and Tarbet in Morar.
Folklore has it that continuing in the thirteenth century King Haakon's Viking Fleet entered Loch Long, and after dragging their longboats overland across the isthmus, they sailed down Loch Lomond causing alarm and terror to the lochside and island inhabitants. They raided the monastery on Inchtavannach and the church on Inchcailloch, before descending the River Leven to rejoin the ocean via the Firth of Clyde. Is it too much to imagine that they may have used Tarbet Isle as a secure marshalling point before setting out to harry the Loch?
A little north-east of Tarbet Is1e and opposite Culness on the eastern shore is the deepest part of the Loch, soundings showing 105 fathoms or 630 feet.