The MV Cardiff Castle is a twin screw passenger vessel, operating on the River Dart in South Devon, UK, mainly on the cruise / ferry route between Dartmouth and Totnes, but also on circular cruises from Dartmouth, for Dart Pleasure Craft Ltd.[1] MV Cardiff Castle was built in 1964 for the River Dart Steamboat Co Ltd (RDSC) by Bolson's of Poole.

She was originally fitted with Totnes Castle's wheelhouse on a flying bridge structure above her main (open) passenger deck.

[2] In 1977 she was sold to Millbrook Steamboat & Trading Co Ltd, then the largest operator of cruises from Plymouth.

In 1985 the Millbrook operation was wound up and there were various transfers of vessels between the fleets of different south Devon companies.

[3] Cardiff Castle returned to the Dart, and can now be seen operating regularly on her original route from Dartmouth to Totnes.