Launched in Basel in 1997, the Aquanaut was a revolution in the world of sport watches by Patek Philippe, a new line resembling the Nautilus, mounted on a rubber strap, a premiere at the firm. The first reference launched was the 5060A with its tapisserie style dial, luminous indexes, rubber strap and a full caseback which was only produced on this reference. This model is most likely one of the pre-series versions, this example differs by having the word “Prototype” inscribed on the dial, a power reserve indicator (very similar to the Patek Nautilus 3710 launched in 1998) and the words engraved on the bridge “330/196 labo No. 04” and of course this special caliber 330/196 to accommodate the power reserve function, one never introduced on the Aquanaut. This is a rare opportunity to acquire a piece never commercialised and the only one ever to be offered on the market. Please note that due to the fact that this is a prototype never intended for sale, an extract from the archives will not be available.