There is a significant difference between the Ordnance Survey (OS) treatment of freshwater and offshore islands. See for example Loch Snigiscleit at grid referenceNF802254. If the islands here were offshore it is virtually certain that there would be three substantial named islands and probably half a dozen named smaller ones. There are several examples – Loch Druidibeag has two named islands and about a dozen un-named. It is not clear whether this because the OS only chose to list a few larger ones and those identified by RCAHMS, or if for some reason local people did not give names to smaller islands in lochs.
Eilean Mhuireill at the south end of the loch (grid referenceNR386673) is identified by the Ordnance Survey as a crannog.
Rainish Eilean Mòr at grid referenceNB388281 is about 27 hectares (67 acres) in extent. This makes it one of the larger freshwater islands, but it is probably the largest relative to the size of the body of water it sits in, Loch Orasaigh being only about 125 hectares (310 acres) all told.
Canny Island at NT891467 is in the middle of the Tweed but on the English side of the border as identified by the Ordnance Survey.
North and South Inch are reclaimed parks on the right bank of the Tay, now within the bounds of the town of Perth.[40] Sleepless Island is now a sewage works at NO146220[41] Bloody Inches is at NO139391 and The Inch at NO106391. Big Island is a former gravel bank at NN992494 and Richards Islands are further upstream on the River Tummel (a tributary of the Tay) at NN955557[42][43][44]
