High Quality Content by WIKIPEDIA articles! The River Dart Steamboat Co Ltd (RDSC) and its predecessors: the Dartmouth Steam Packet Company and the Dartmouth and Torbay Steam Packet Company were the major ferry and excursion boat operators on the River Dart in South Devon for 120 years, until its demise in 1976. The company was famous for its distinctive paddle steamers, which were a familiar sight on the river until the late 1960s.