Firth locally the change is held to be at the Tail of the Bank where the river crosses a sandbar off Greenock at the junction to the Gare Loch, or even further west at Gourock point. However, some firths are exceptions. The Cromarty Firth on the east coast of Scotland, for example, resembles a large loch with only a relatively small outlet to the sea and the Solway Firth and the Moray Firth are more like extremely large bays. The Pentland Firth is a strait rather than a bay or an inlet. These are connected to, or form part of, the
Geography of Scotland Harris (referred to as two islands but actually just one) is the largest island surrounding Scotland. Many of these offshore 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 the "Grey Dog" between Scarba and Lunga. There are also numerous clusters of islands in the Firth of Forth and the Firth of Clyde and in freshwater lochs such as Loch Lomond and Loch Maree. Outlying islands include St