MV Saturn now MV Orcadia was a ro-ro passenger and vehicle ferry operated by Caledonian MacBrayne in the Firth of Clyde in Scotland between 1978 and 2011, operating the Rothesay crossing for the first decade of her career and eventually saw service on the Dunoon and Brodick crossings as well. After lengthy lay-up, she was sold in 2015 to Pentland Ferries to be converted for ferry services and work with the renewable energy sector around Orkney and the Pentland Firth.