''Arno XI'' is a hydroplane conceived by . Designed to break

water speed record The world unlimited water speed record is the officially recognised fastest speed achieved by a water-borne vehicle, irrespective of propulsion method. The current unlimited record is , achieved by Australian Ken Warby in the ''Spirit of Austra ...

s, it was built between 1952 and 1953 by the Cantiere Timossi boatyard, located in Azzano (a

frazione A ''frazione'' (: ''frazioni'') is a type of subdivision of a ''comune'' ('municipality') in Italy, often a small village or hamlet outside the main town. Most ''frazioni'' were created during the Fascist era (1922–1943) as a way to consolidat ...

Mezzegra Mezzegra is a former ''comune'' (municipality) in the Province of Como in the Italian region Lombardy. Since 21 January 2014 it is part of the comune of Tremezzina. Geography It lies on the northwestern shore of Lake Como between Tremezzo and Len ...

) on the shores of

Lake Como Lake Como ( , ) also known as Lario, is a lake of glacial origin in Lombardy, Italy. It has an area of , making it the third-largest lake in Italy, after Lake Garda and Lake Maggiore. At over deep, it is one of the deepest lakes in Europe. ...

. Castoldi persuaded Ferrari, via its racing drivers

Alberto Ascari Alberto Ascari (13 July 1918 – 26 May 1955) was an Italian racing driver, who competed in Formula One from to . Ascari won two Formula One World Drivers' Championship titles, which he won in and with Ferrari, and won 13 Grands Prix across ...

and

Luigi Villoresi Luigi "Gigi" Villoresi (16 May 1909 – 24 August 1997) was an Italian racing driver, who competed in Formula One from to . Villoresi contested 34 Formula One Grands Prix across seven seasons for Italian teams Ferrari, Maserati, Lancia, and C ...

, to supply him with the same power unit used in the

Ferrari 375 F1 :''See also the 340 and 375 road cars sharing the same engine'' After finding only modest success with the supercharged 125 F1 car in Formula One, Ferrari decided to switch for 1950 to the naturally aspirated 4.5-litre formula for the series. ...

. The engine was installed in a Timossi three-point racing hydroplane hull. Castoldi managed to further increase horsepower by attaching two superchargers. The result was a 502 bhp speedboat, which he used to hit a 150.19 mph top speed in October 1953 on Lake Iseo. This world speed record for an 800 kg boat still stands today. A similar hydroplane was constructed by

Guido Monzino Count Guido Monzino (2 March 1928 – 11 October 1988) was a twentieth-century Italian mountain climber and explorer. In 1973, he led the first Italian expedition to climb Mount Everest. Biography Monzino was born on 2 March 1928 in Mil ...

in 1954. Like ''Arno XI'', it utilizes a Lampredi engine, in this case sourced from a wrecked

Ferrari 375 MM :''See Ferrari 375 F1 for the 375 used in Formula 1 racing, and 375 America, a GT car'' The Ferrari 375 MM, was a sports racing car produced by Ferrari from 1953 to 1955. It was named "375" for the unitary displacement of one cylinder in the 4. ...

Today

''Arno XI'' was later sold and raced in numerous competitions, finally retiring in 1960. It has since been restored and is expected to go for up for sale by

RM Auctions RM Sotheby's is a collector car auction company headquartered in Blenheim, Ontario, Canada, with offices across the United States, Europe, and the Middle East. The company specializes in the sale of classic, vintage, sports, and exotic cars, and ...

for up to €1.5m. In 2021 the ''Arno XI'' is for sale again at an asking price of USD$12 Million.

References

{{Ferrari Racing motorboats Hydroplanes Ferrari