With "Rothesay Ferry" emblazoned on her hull, "Saturn" operated primarily on the Wemyss Bay – Rothesay crossing for much of her first decade. From 1986, a new rostering policy saw the three streakers switching between the Rothesay and Dunoon routes. The third vessel provided additional peak sailings on both crossings, served Kilcreggan and, between 1993 and 1999, provided cruises on summer afternoons. Later, there were two vessels at Rothesay for most of the day with the former Western Isles' ship providing additional capacity. After more than 35 years, the Streakers were replaced by a new generation of CalMac ferries designed for the Upper Firth, just as in the 1970s they had replaced an earlier generation. came into service on the Rothesay route in 2005, followed by in 2007. With "Bute"'s introduction, "Saturn" moved down the firth to Ardrossan, assisting on the Brodick crossing during summer, and acting as a spare vessel during the winter. Major work at Rothesay throughout the winter of 2006/2007 required the vastly superior maneuverability of the 'Streakers' for access to the pier and "Saturn" with sister ship "Juno" were in service for the duration of the winter while newer ships "Bute" and were laid up. This continued until April 2007 when the newer ships could resume service. Sister ship of "Bute", entered service the following month which allowed "Saturn" to return to her summer duties at Arran. In September 2007 "Saturn" became the first and only 'streaker' to leave the Firth of Clyde when she carried out berthing trials at Port Ellen, Port Askaig and Kennacraig to test her suitability on the Islay service. "Saturn" also carried out special cruises from Gourock and Dunoon to mark the return of Cunard liner to the Firth of Clyde upon the liner's 40th anniversary in 2007 and her final visit to the Clyde in 2008. "Juno" was taken out of service in 2007, and laid up at Rosneath until she was dismantled there in 2011. In October 2010, "Saturn" took over the Dunoon sailings from older sister "Jupiter", which was laid up at Rosneath as spare vessel for that winter, although she never saw service again, and on 25 June 2011 she was towed away to be broken up in Denmark.