Cuan Sound is a narrow channel, 200 metres (656.2 ft) wide, in Argyllshire, western Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. It separates Seil Island and Luing

Luing

Luing is one of the Slate Islands, Firth of Lorn, in the west of Argyll in Scotland, about 16 miles south of Oban. It has a population of around 200 people, mostly living in Cullipool, Toberonochy , and Blackmillbay...

 and later becomes the Firth of Lorn. It has a very strong current. The Cuan Ferry service crosses the sound. In Cuan Sound, the north-going stream begins 4.5 hours after high water and sets westward; the south-going stream begins 1.5 hours before high water and sets eastward; the streams attain a rate of 7 knots at springs. This coast from Cuan Sound to Easdale Bay is in many places foul and rocky for 1.5 cables of it. Sgeir na Faoileann, a rock above water, one cable from the shore, and 3.5 cables northward of the entrance to Cuan Sound, is surrounded by foul ground, which extends 1.5 cables south-westward from it. Coirebhreacain

Gulf of Corryvreckan

The Gulf of Corryvreckan , also called the Strait of Corryvreckan, is a narrow strait between the islands of Jura and Scarba, in Argyll and Bute, off the west coast of Scotland.It is possible for tourists to visit the site by way of boats trips from local harbours.- Topography...

and Cuan Sound are seldom attempted except near slack water.