Breaking the world water speed record
In the 1950s, Achille Castoldi, a champion outboard racer, was looking to break the world speed record on the water. He approached Enzo Ferrari to propose the construction of a boat, unique in its kind.
The industrialist at the head of the brand assigned his best engineers to the project, and got personally involved. The boat was built by the Cantieri yard in Timossi Azzano on Lake Como, Italy. The hydroplane is made of steel, wood and mahogany and weighs 800 kg.
Adapting an automobile engine
To be fast, the Arno XI needs a powerful engine. In 1952, Ferrari made its Formula 1 debut, but its engines were already proving to be incredible. Engineers chose to equip the boat with a 12-cylinder, 4.5-liter 375m engine, designed for the Ferrari 375. But the similarities end there.
Initially delivering 350 hp for cars, Castoldi did not find it sufficient for his boat. The manufacturer then developed a series of "firsts" to adapt it to the marine world. Starting with a methanol fuel. They then developed two ignition magnetos so that the engine would continue to function even when covered with water. 24 spark plugs replaced the usual 12, two compressors and two carburetors with four starters as well as a customized gearbox completed the set. The final result is a power of 500 hp, 150 hp more than on its car equivalent! The boat was then painted in the brand's colors, a flamboyant red.
Record broken!
On October 15, 1953, Castoldi broke the world speed record (under 800 kg) on Lake Iséo, Italy, with an average speed of 242 km/h (131 knots!). A record not beaten to date. Some time later, the pilot broke a new record on the 24 nautical mile event.
4 owners, who will be next?
Since then, the boat has had three different owners. The second was Nando Dell'Orto, who piloted the Arno XI until 1968. It was then stored in a warehouse for more than 25 years. In the 1990's, Luciano Mombelli, a Ferrari enthusiast, bought it and gave it a complete overhaul in the Ferrari factory. The boat is now back to its former splendor and its original characteristics, keeping its 1952 engine capable of producing 500 hp, 40 years later.
In 2012, the Arno IX was bought back by its 4th and current owner. It was in fact on display for a while at the Ferrari museums in Modena and Maranello. Today, the boat has been repatriated to the United States, to its owner, and is now quickly seeking a new buyer. Without being a car, this boat is one of the rarest Ferrari models ever built and the only one of its kind.
In very good condition, and ready to sail again, the Arno XI is for sale at 9,895,800 euros.
