MV Cowal in 1954. She inaugurated the regular Wemyss Bay to Rothesay car ferry service, on 1 October 1954 and remained in the upper Clyde for her whole career. From 1957 the three "A, B, C" sisters were working interchangeably. In May 1970, "Cowal" inaugurated a short-lived seasonal Fairlie-Tarbert-Brodick service. When this ended in September 1971, "Cowal" operated between Largs and Millport, until displaced in March 1972 by the former Skye ferry on the quicker Largs to Cumbrae Slip run. With linkspans at Gourock and Dunoon, the hoist-loading "Bute" and "Cowal" were restricted to the Wemyss Bay to Rothesay crossing, where "Cowal"
Highland Boundary Fault Border suggests that rocks along both ends of the fault plane are indistinguishable from one another, with no brecciation. Aligned southwest to northeast from Lochranza on Arran, the Highland Boundary Fault bisects Bute and crosses the southeastern parts of the Cowal and Rosneath Peninsulas, as it passes up the Firth of Clyde. It comes ashore near Helensburgh, then continues through Loch Lomond. The loch islands of Inchmurrin, Creinch, Torrinch, and Inchcailloch all form part of the Highland Boundary Fault. From Loch Lomond the Highland Boundary Fault continues to Aberfoyle, then Callander, Comrie and Crieff. It then forms the northern boundary