The only boat powered by a Ferrari F1 engine is up for sale

The Timossi-Ferrari Arno XI hydroplane last sold at auction for €868,000. VALERY HACHE/AFP/GettyImages

The only speedboat powered by a Ferrari F1 engine is up for sale -- and if you have to ask how much it costs, you probably can't afford it.

In 1952, Italian speedboat racer Achille Castoldi set his sights on the water speed record for an 800kg boat. In order to achieve it, he commissioned a new three-point hydroplane from the Cantieri Timossi boatyard on Lake Como and set about finding a suitable engine supplier.

Having lost an Alfa Romeo engine deal to main rival Mario Verga, Castoldi was introduced to Enzo Ferrari by his racing driver friends Alberto Ascari and Luigi Villoresi. Ferrari had not built an engine for nautical use before, but legend has it he was impressed by Castoldi's efforts to hide two Alfetta 158 race cars from German forces during the Second World War and agreed to supply an F1-specification V12 Tipo 375 engine.

The result was the unique Timossi-Ferrari Arno XI Hydroplane.

With 385bhp lurking under its Rosso Corsa engine cover and a mahogany veneer covering its wooden hydroplane, Arno XI was primed to chase the record it had been built for. Initial test runs in January 1953 saw Castoldi record an unofficial top speed of 124mph, but it soon became clear it wouldn't be enough as Verga set a new 800kg record with a two-way average of 140.74mph.

Unperturbed, Castoldi went back to Ferrari to have the engine rebuilt and upgraded. Maranello's engineers were let off the leash and converted the engine to run on methanol, while adding two huge superchargers and two spark plugs per cylinder. The result was an increase in power to over 600bhp.

On October 15, 1953, Castoldi made a new record attempt on Lake Iseo, achieving a two-way average of 150.19mph over a flying kilometre -- a record that still stands 66 years later.

Following a crash in a 1,700kg hydroplane and the death of Vega in a separate accident, Castoldi retired from the sport and in 1958 sold Arno XI to gentleman-racer Nando dell'Orto. Under its new ownership, Arno XI was converted to race in circuit championships, resulting in the distinctive air intake and rear fin it still has today for extra aerodynamic stability.

After considerable success, dell'Orto retired from competition in 1968 and Arno XI was stored in a Milanese warehouse for the best part of 25 years. Just as it was on the verge of rotting away, it was bought by a new owner in the early 1990s and restored to its racing prime. The V12 engine was sent back to Ferrari so that it could be converted to run on unleaded petrol and, according to auction papers in 2012, achieved an output of 700bhp on a test bench.

Arno XI was last sold in Monaco in 2012 for a price of €868,000 at auction and has since been on display at Ferrari's museum in Modena. It is now up for sale again through Du Pont Registry and comes with stacks of historical documents, including Castoldi's original water speed record certificate from 1953.