<P> This is a list of islands of Scotland, the mainland of which is part of the island of Great Britain . Also included are various other related tables and lists . 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". </P> <P> Scotland has over 790 offshore islands, most of which are to be found in four main groups: Shetland, Orkney, and the Hebrides, sub-divided into the Inner Hebrides and Outer Hebrides . There are also clusters of islands in the Firth of Clyde, Firth of Forth, and Solway Firth, and numerous small islands within the many bodies of fresh water in Scotland including Loch Lomond and Loch Maree . The largest island is Lewis and Harris which extends to 2,179 square kilometres, and there are a further 200 islands which are greater than 40 hectares in area . Of the remainder, several such as Staffa and the Flannan Isles are well known despite their small size . Some 94 Scottish islands are permanently inhabited, of which 89 are offshore islands . Between 2001 and 2011 Scottish island populations as a whole grew by 4% to 103,702 . </P> <P> The geology and geomorphology of the islands is varied . Some, such as Skye and Mull are mountainous, while others like Tiree and Sanday are relatively low lying . 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 . Many of the islands are swept by strong tides, and the Corryvreckan tide race between Scarba and Jura is one of the largest whirlpools in the world . 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 . </P>

How many inhabited islands are there in scotland