The definition of an offshore island used in this list is "land that is surrounded by seawater on a daily basis, but not necessarily at all stages of the tide, excluding human devices such as bridges and causeways".
Many have bedrock made from ancient Archaean Lewisian Gneiss which was formed 3 billion years ago; Shapinsay and other Orkney islands are formed from Old Red Sandstone, which is 400 million years old; and others such as Rùm from more recent Tertiary volcanoes.
[5] Other strong tides are to be found in the Pentland Firth between mainland Scotland and Orkney, and another example is the "Grey Dog" between Scarba and Lunga.
[2] A feature of modern life in the islands is the low crime rate, and they are considered to be among the safest places to live in Britain.
[8][9] However, despite no possession by any other state and other precedents, the legality of the claim is disputed by the Republic of Ireland, Denmark and Iceland, and some say it may be unenforceable in international law.
[Note 2] The local government council areas with the most inhabited islands are Argyll and Bute with 23, Orkney with 20, Shetland with 16 and Highland and Comhairle nan Eilean Siar with 14 each.
Losses were severe in many areas during the 19th century when islands such as Pabbay and Fuaigh Mòr were subject to forcible evictions during the Highland Clearances.
The overall trends are typically growth in populations in the early part of the modern period, followed by declines from the mid 19th century onwards.
In every case except Orkney the highest population was recorded prior to 1932 and the lowest post-Industrial Revolution figure after 1960.
[3] The Scottish Community Alliance noted that "the largest rate of increase has been in the Western Isles (6%) where local people now own approximately 60% of the landmass.
"[20] The following table compares the populations of the main Scottish archipelagos with that of the Faroe Islands for a similar time frame to the above.
[38] This is a list of Scottish islands that either have an area greater than 40 hectares (approximately 100 acres) and/or are inhabited.
The main groups, from Haswell-Smith (2004), in many cases provide a more useful guide to location than local authority areas.
[13] These following are listed by the National Records of Scotland as "included in the NRS statistical geography for inhabited islands but had no usual residents at the time of either the 2001 or 2011 censuses.
Although greater than 40 hectares in size it fails to meet the definition of an island used in this list as it is only surrounded by water during occasional spring tides and storms.
[62] Dùn in St Kilda is separated from Hirta by a shallow strait about 50 metres (160 feet) wide.
There is no commonly accepted derivation for "Burntisland" which had numerous other forms in the past, such as "Brintilun" and "Ye Brint Eland".
[63] Gluss Isle at the western entrance to Sullom Voe is one of the many promontories in Orkney and Shetland connected to a larger body of land by an ayre.
The name "Inch" (Innis) can mean island (e.g. Inchkenneth, Inchcolm), but is also used for terra firma surrounded by marsh e.g. Markinch, Insch.
"-holm" is also common as a suffix in various landlocked placenames, especially in the far south of mainland Scotland e.g. Langholm, Kirk Yetholm, Holmhead (by Cumnock), Holmhill (next to Thornhill, Nithsdale).
The name Easdale appears to be the combination of eas, which is Gaelic for "waterfall" and dal, the Norse for "valley".
In July 1967, 15 million people watched the climbing of the Old Man of Hoy live on BBC television.
Today, crannogs typically appear as small, circular islands, between 10 and 30 metres (30–100 feet) in diameter.