The Clypse Course was a 10.79-10.95-mile, 34-turn street circuit through Onchan parish, introduced in 1954 to bring back the Lightweight, Ultra-Lightweight and Sidecar TT races, and used through the 1959 season before those classes returned to the Mountain Course. From the Grandstand it shared Bray Hill, Parkfield Corner and Willaston Corner with the Willaston Circuit, then ran its own loop past Ballacarrooin (the course's high point at 856 ft, OS grid SC 406 827) to rejoin the Mountain Course in reverse at Cronk-ny-Mona, out to Creg-ny-Baa, back down the Onchan-Laxey road to the Manx Arms, up through the Nursery Curves to Signpost Corner, and on to the finish. Carlo Ubbiali and Tarquinio Provini each won four races on the course, MV Agusta won eight of the ten manufacturer's titles contested, and Inge Stoll became the first woman to compete in an Isle of Man TT race here in 1954; Provini set the outright lap record in 1959 at 80.42 mph. No turn-by-turn coordinate list for the course was found in the sources checked; most of its distinctively-named points either duplicate Willaston Circuit or Mountain Course landmarks already covered, or (Ballacarrooin, Nursery Curves, Manx Arms) have no independently sourced coordinate.