MV Sound of Jura was the first drive-through car ferry on the west coast of Scotland.

Western Ferries were unable to compete with this subsidised service and began to lose traffic.

Estimating that this was equal to their own total running costs, they ran a free return crossing on 13 June 1975.

In September 1976, Sound of Jura was sold to the Mexican Government and renamed Quintana Roo.

[5] In Mexico, Quintana Roo opened up a new car ferry route between Puerto Morelos, on the Yucatán Peninsula and the island of Cozumel.