Ken Warby (born 9 May 1939) is an Australian motorboat racer, who currently holds the Water speed record of 317.60 miles per hour (511.13 kilometres per hour). This was set in Blowering Dam, part of the Snowy Mountains hydro-electric scheme, near Tumut, New South Wales, roughly 250 miles (400 km) south-south west of Sydney, on 8 October 1978.