Evansville used to play host to the top tier boat racing circuit of H1 Unlimited when it hosted Thunder on the Ohio along the Ohio River in downtown Evansville, which was hosted continuously from 1979 to 2009. Evansville had also previously hosted Thunder on the Ohio from 1938 to 1940. The 2 mile Evansville tri-oval was known as one of the fastest hydroplane courses in the world, as various world records were set on the Evansville course. Hydroplane racing returned to Evansville in 2017, with the introduction of the Evansville Hydrofest, an American Power Boat Association event.