A Ferrari-engined hydroplane racing boat that was once the holder of the water speed record will be offered for sale at an auction in May. The 1953 ARNO XI Hydroplane was the brainchild of Achille Castoldi, a friend of Ferrari grand prix drivers Alberto Ascari and Luigi Villoresi, who convinced Enzo Ferrari to help develop the boat. Ferrari supplied a 4.5-litre V12 engine (as used in the Type 375 grand prix car), complete with twin superchargers and more than 600bhp. On October 15, 1953, the G.P. 52/1 Nautico engine took the hydroplane to a top speed of 150.19mph, setting a record for an 800kg boat. ARNO XI was then sold to Nando dell\'Orto, who raced it successfully for more than 10 years. So successful in fact was the boat that many of its records still stand today. The boat was sold to its current owner 20 years ago, and has since been restored to concours condition. \"This awe-inspiring racing boat has beauty, history, provenance and performance; it simply ticks every box for any serious collector,\" said Peter Wallman, specialist at RM Europe, which is selling the ARNO XI in its Monaco auction on May 11-12.