You may not know it, but Ferrari powered a powerful Hydroplane back in the 1950s. It was built for one thing: breaking the World Speed Record on the water. Achille Castoldi, a racing champion, proposed such a boat to the one and only Enzo Ferrari who agreed to help him in the endeavor.

1952 Ferrari Arno XI Racing Boat

DESIGN

Arno XI was built to shatter the speed record in the 800-kg class. Achille Castoldi had been setting records on the water since 1940. To achieve the speed record, he commissioned Cantieri Timossi to build a 3-point hydroplane from hardwood, covered in a mahogany veneer. When Enzo heard he had painted the upper body in Ferrari Red, the Scuderia F1 team was sent to lend their expertise. This culminated in a world record in the flying kilometer: 150.49 mph, which still stands to this day.

POWER

Initially, Castoldi had planned to use a Ferrari engine, so he purchased a 4.5L V12. It was identical to the 385 horsepower “Lampredi” engine used in the Ferrari 375. Once Enzo realized he was going for the record, he sent his Chief Engineer along with a race-prepped Grand Prix engine. Stefano Meazza and a few of the Scuderia team members realized they needed more power. Using lessons learned on the track, they nearly doubled the compression ratio to handle methanol. A hotter spark was needed, so the distributors and coils were replaced by twin magnetos. Each cylinder had twin spark plugs to ensure a clean burn. It wasn’t enough, so two giant superchargers were driven by the crankshaft. Each one had its own Weber 4-Barell modified to dump meth into the engine with an air/fuel ratio of 5:1. What started at 385 horsepower made between 550 and 600 in race tune.

HISTORY

Once he broke the record, Castoldi built another boat for a different class. However, the engine exploded and he retired from racing. The Arno XI was sold to Nando dell’Orto, an engineer who revised the aerodynamics for better stability. After adding a few pounds, he came in 2nd place for the 900 kg class in 1965. It has since been seen occasionally at boat shows doing parade laps, and it led a peaceful retirement. But because it is the only boat to ever have been powered by Scuderia Ferrari, it is being completely restored by Ferrari Classiche.

Now, this Ferrari is for sale and looking for a new owner. It comes with a well-documented history file that includes hundreds of period photographs and handwritten notes from Ferrari’s engineers. The boat is currently being certified at Ferrari Classiche, and a copy of the U.I.M. record certification that attests to Achille Castoldi’s 1953 speed record is included as well. It is the ultimate Ferrari for the ultimate Ferrari collector.   

• Achille Castoldi’s famed Ferrari V-12 Timossi 800 kg class racing hydroplane • Reset the world speed record in its class on 15 October 1953, at 241.708 km/h • Beautifully and painstakingly restored; engine confirmed original by Ferrari S.p.A. • Accompanied by an extensive historical file, including a copy of the U.I.M. record certificate no. 329 and Nando Dell’Orto’s original racing logbook • Unique, instantly recognisable, achingly beautiful and immensely historic

The ‘three-point’ hydroplane, devised in America during the late 1930s by Adolph and Arno Apel of New Jersey’s Ventnor Boat Works, truly revolutionised speedboat design. Elegantly simple, the Apel design divided the ‘step’ portion of the hull into two pontoon-like surfaces, or sponsons, with each on opposite sides of the boat. The boat’s propeller acted as the ‘third point’ in the equation. The tunnel between the sponsons trapped air to generate aerodynamic lift, with only the sponsons and propeller in direct contact with the water whilst the boat was at speed.

Italy’s premier speedboat racer was Achille Castoldi, a cousin of M.C. 72 designer Mario Castoldi and a highly talented driver and engineer in his own right. Beginning in 1940 with his original ‘Arno’, a 400 kg-class boat with a Picciotti-built hull and Alfa Romeo Type 158 power, Castoldi reset the world speed record at 130.517 km/h (81.10 mph). Subsequent boats in the ‘Arno’ series followed, with most powered by Alfa Romeo and at least one Maserati-powered example, and he primarily competed in circuit-type hydroplane racing. After 1951, Castoldi ended his relationship with Alfa Romeo and changed his focus to world speed-record competition, now seeking a new engine supplier for an attempt on the 800 kg class world speed record.

Castoldi’s record preparations began in 1952, when he travelled to Maranello with his two close friends, famed racing champions Alberto Ascari and Luigi Villoresi, to order a Formula 1 specification V-12 engine from Ferrari. The blessing of Il Commendatore, Enzo Ferrari, was virtually assured since Castoldi had earlier managed to save a number of Alfetta 158 race cars during the war, keeping them hidden from the occupying German forces at his factory in Abbiategrasso, near Milan.

The Aurelio Lampredi-designed Tipo 375 V-12 engine, the same unit that powered Ferrari’s Grand Prix racing cars during 1951 and achieved Ferrari’s first ever World Championship Grand Prix win with Froilan Gonzalez in 1951 and helped Ascari to earn Ferrari the World Championship in 1952, was selected to power Castoldi’s new boat. It developed some 385 bhp with 12:1 compression and a dual-magneto ignition system, driving a twin-blade propeller via a gearbox at up to 10,000 propeller revolutions.

Castoldi’s boat, dubbed ‘Arno XI’, was built to a three-point hydroplane design by Timossi Azzano’s Cantieri Timossi boatyard located on Lake Como. A beautiful example of form and function in equal parts, the hydroplane featured a solid wood-framed structure skinned by marine-grade plywood with a mahogany veneer, a strong separate metal subframe chassis to cope with the enormous power and the engine cover and cockpit exterior appropriately finished in Rosso Corsa.

Once completed, ‘Arno XI’ was shaken down at the Campione d’Italia races in January 1953, with Castoldi reaching an unofficial top speed of 124 mph, prior to attempting an officially sanctioned two-way run. Castoldi’s main competitor, Mario Verga, who received the full factory support of Alfa Romeo, went on to set a new 800 kg class speed record of 202.26 km/h (125.68 mph) with his Alfa Romeo 159-powered boat, ‘Laura’. Adding emphasis, Verga reset the record just two weeks later with a two-way top speed of 226.50 km/h (140.74). Undaunted, Castoldi had the 4.5-litre Tipo 375 F1 V-12 engine rebuilt and highly modified, with official Ferrari support, including Stefano Meazza, Scuderia Ferrari’s chief race engineer who oversaw the engine preparations for Castoldi. This time, the already highly powerful Ferrari V-12 racing engine was tuned to operate on methanol, now allowing much higher engine compression, in conjunction with twin superchargers and twin four-choke carburettors, with power output now exceeding 600 bhp, representing a power increase of some 200 bhp over the original specification!

Once upgraded and readied for competition, Castoldi made his record attempt at Lake Iseo on the morning of 15 October 1953, with Alberto Ascari and Luigi Villoresi in attendance, clearly demonstrating Ferrari’s support of the project. Now, Castoldi finally achieved his objective, with ‘Arno XI’, by breaking the speed record in the 800 kg class with a two-way average speed in the flying kilometre of 241.708 km/h (150.19 mph). Later that day, Castoldi followed up with a new record in the 24 nautical mile event by achieving an average speed of 164.70 km/h (102.34 mph).

The year following these triumphs, Achille Castoldi survived a frightful engine failure in an aircraft engine-powered, 1,700 kg Cantieri Timossi-built hydroplane. The death of his racing nemesis, Mario Verga, soon followed in an unrelated hydroplane accident, and Castoldi retired from competition. His victorious ‘Arno XI’ was placed into storage for a few years prior to acquisition in 1958 by engineer and gentleman-driver Nando Dell’Orto, who ran it in the circuit championships, where it was pitted, amongst others, against the powerful Maserati 450S V-8 driven raceboats.

Under Dell’Orto, the silhouette of ‘Arno XI’ was continually updated by the Milan-based Carrozzeria Boneschi with a very original and more aggressive engine fairing with a “shark nose” intake and a large vertical stabilising fin at the rear. As revised, ‘Arno XI’ achieved several fastest-lap records and three titles, including the European Championship in 1963. Nando Dell’Orto retired from competition in 1968, leaving ‘Arno XI’ in the huge warehouse of his paper-manufacturing plant located in the Milanese suburbs. It is here that this famous racing hydroplane was located and saved from oblivion. A painstaking restoration of this historic, record-setting hydroplane was commissioned by the new owner in the early 1990s. Photos of the boat before and during restoration are available for review in the history file

. The glorious V-12 engine was returned to Maranello, where it revived fond memories for several mechanics who had first worked on it in 1953. Engine work included the rebuilding of the two overhead camshafts and replacement of all the valves, whilst the manufacturer’s workshop reconditioned the dual four-choke carburettors. Not one vital mechanical part escaped scrutiny and appropriate treatment, including the twin superchargers that made this unique Ferrari 375 F1 engine capable of, in fact, producing up to 700 bhp during a bench test after its rebuild. However, it should also be noted that it was converted, at this time, to run on 100 Octane unleaded fuel rather than methanol to improve reliability and usability.

As for the hull, the Bisoli boatyard, located in Sirmione on Lake Garda, checked and restored the entire structure. Laminated panels were specially ordered from Canada for the construction of a new deck, a must for racers that are put under severe strain, as it contributes greatly to the rigidity of the hull. Particular care was taken in the restoration of the steering system, propeller shaft and the razor-sharp twin-blade propeller, whose speed can exceed more than 10,000 rpm. Nando Dell’Orto had exchanged the steering wheel in 1958, but thankfully, he retained the old Bugatti four-spoke steering wheel used by Achille Castoldi during his world-record attempts, and this is the same one that is mounted on the boat today.

Once carefully restored and impressively presented in its period and now in its most highly developed form under the ownership of Nando Dell’Orto, ‘Arno XI’ has returned to the water for spirited runs since 2004, and it has received honours from the Galleria Ferrari, having been welcomed by Piero Ferrari, who warmly congratulated the craft’s present owner for the thoroughness, authenticity and high quality of the restoration of this unique, record-setting Ferrari V-12-powered hydroplane racer, an effort truly commensurate with the stature of this legendary craft. The hard work has included years of extensive historical research to collect a truly rich body of documentation and photographs accompanying the sale of ‘Arno XI’, including technical worksheets from Ferrari’s Maranello engine shop, dated September 1953. Notably, Ferrari Classiche has recently confirmed with RM Auctions that the Tipo 375 F1 V-12 engine, number G.P. 52/1, currently installed in ‘Arno XI’, is indeed original, and a declaration confirming this fact accompanies the sale of this record-setting hydroplane