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
Firth of Clyde each other. Sometimes called the Clyde Waters, this water body is customarily considered an element of the Irish Sea. The ferry services are run by Caledonian MacBrayne and by Western Ferries and many of the routes are lifeline services for communities living in remote areas. A great number of sea lochs adjoin the Firth, the largest being Loch Fyne. The Cowal peninsula extends into the Firth of Clyde and forms the main upper firth west shoreline. The main town on the Cowal peninsula is Dunoon. These routes across the Firth of Clyde save time, rather than traveling "round by road",