Last summer, we told you about the one-of-a-kind BMW speedboat.

Now here’s something that makes it look like a mere child’s toy:

The 1953 Ferrari Hydroplane “Arno Xi,” which has been added to the lineup at RM Auctions‘  highly anticipated Monaco sale on May 11-12.

Click to enlarge; Silvano Maggi, courtesy of RM Auctions

The Arno XI was the brainchild of Achille Castoldi, a friend of famed Ferrari Grand Prix drivers Alberto Ascari and Luigi Villoresi, who wanted to break the world water speed record.

He built the eye-popping craft with help from Enzo Ferrari and one of his 12-cylinder, 4,500 cc V12 Ferrari engines—the very same as that installed in Ferrari’s winning Type 375 Grand Prix car.

Click to enlarge; Silvano Maggi, courtesy of RM Auctions

With the addition of twin superchargers that developed in excess of 502 hp at 6,000 rpm, Castoldi did indeed set a new world record in October of 1953, hitting 150.19 mph on Lake Iseo in northern Italy.

Estimated at up to about $2 million, the unique craft is sure to generate serious action from collectors.

And how cool would it look if you cruised up to the yacht club dock in this little bastard?