According to Official Guinness Records,
The highest recorded speed by a hovercraft is 137.4 km/h (85.38 mph), by Bob Windt (USA) at the 1995 World Hovercraft Championships on the Rio Douro River, Peso de Regua, Portugal. Windt was driving a streamlined 5.8 m (19 ft) Universal UH19P hovercraft called Jenny II, with a 82 kW (110 hp) V6 car engine driving its two fans (one at the rear to provide propulsion, and one underneath to provide lift). Weight of hovercraft is 392 kg (1,050 lb). Speed was measured over a flying kilometre.
For a complete list of 1995 records, please visit 1995 Guinness Records in Portugal.