Lunga is one of the Slate Islands in the Firth of Lorn in Argyll and Bute, Scotland. The "Grey Dog" tidal race, which runs in the sea channel to the south, reaches 8 knots in full flood. The name 'Lunga' is derived from the Old Norse for 'isle of the longships', but almost all other place names are Gaelic in origin. The population was never substantial and today the main activity is an adventure centre on the northern headland of Rubha Fiola. The surrounding seas are fished for prawns and scallops and there is a salmon farm off the south eastern shores. The National Scenic Area of which the island is part, hosts a growing number of outdoor leisure pursuits.
Lunga is 2 kilometres (1.2 mi) west of the island of Luing and just north of Scarba. The nearest town is Oban some 16 kilometres (9.9 mi) to the north. The channel to the south, Bealach a' Choin Ghlais (pass of the grey dog), is only 200 metres (220 yd) wide and is scoured by the notorious 'Grey Dog' tidal race which reaches 8 knots when in full flood. According to an 1845 description:
'... About 1 cable broad, and the stream of water during the greater part of ebb and flood rushes along the narrow pass with much violence. So great is the overfall on the current, that even during moderate tides it is impossible to force a boat through'.<ref> Whirlpool Scotland Retrieved 26 February 2007. This source is quoting Gillies, Patrick H. (1909) NetherLorn - Argyllshire and its Neighbourhood. London. Virtue & Co.</ref>
This strait is sometimes called the 'Little Corryvreckan' after its greater cousin between Scarba and Jura just a few miles to the south.<ref>http://web.archive.org/web/20060212124445/http://www.bsactravelclub.co.uk/reports/corryveckan.htm (accessed 10th July 2014)</ref>
There are numerous islets in the surrounding waters. To the north is the isle of Belnahua and to the north west are Eilean Dubh Mor and the Garvellachs. Due west there is only Dubh Artach lighthouse between Lunga and the open Atlantic Ocean. At high tide the northern tip of Lunga becomes several separate islets with Rubha Fiola (headland of the tidal island) to the north, then Fiola Meadhonach (middle tidal island), Eilean Ioasal (humble island) and Fiola an Droma (drum-shaped tidal island) closest to Lunga proper. All around are smaller skerries and islets, including Eilean a' Bhealaich (island of the pass), Guirasdeal to the south west and Fladda to the north.<ref>Haswell-Smith, Hamish (2004)</ref>
This complexity of land and sea coupled with the strong tides makes these the most treacherous channels on Scotland's west coast.<ref> Murray, W.H. (1977) The Companion Guide to the West Highlands of Scotland. London. Collins.</ref>
The highest point is Bidean na h-Iolaire (peak of the eagle) and the main bay is Camas a Mhor-Fhir (bay of the giant) to the south which provides an escape route from the Grey Dog.<ref> Most English sources such as Murray (1977) tend to call the tidal current the Grey Dog (singular), although Haswell Smith (2004) and various websites refer to the 'Grey Dogs' (plural). The latter is consistent with the original Gaelic, although not the associated legend. It is possible that the English use of the singular is intended to refer to the tidal race, and the plural to the many standing waves it creates.</ref>The only other anchorage for passing yachts is at Poll nan Corran (the sickle shaped pool), on the east coast, which has a pebble beach.
There are only three houses on the island and it is primarily used for grazing animals. In 2001 the island had a population of 7 but in 2011 there were no "usual residents" living there as recorded by the census.<ref>National Records of Scotland (15 August 2013) (pdf) Statistical Bulletin: 2011 Census: First Results on Population and Household Estimates for Scotland - Release 1C (Part Two). "Appendix 2: Population and households on Scotland’s inhabited islands".</ref>