High-speed Sea Service is the name of a class of high-speed craft developed and operated by Stena Line, for European international ferry traffic. The HSS 1500 are the largest "fastcraft" in the world and have an in-service speed of 40 knots (75 km/h).
Sea - Ferries
Several patents were registered to Stena Line in the development of the HSS, and four vessels were ultimately completed during the late 1990s; Stena Discovery, Stena Explorer and Stena Voyager were built to operate around the British Isles with Stena Carisma built for Scandinavian use.
Links: www.stenaline.co.uk, en.wikipedia.org