Yesterday, @ 富 艺 斯 广告 行 PHILLIPS auctioned a rare Rolex Sea-Dweller series prototype watch Ref.1665, and the final transaction price was as high as 700,500 Swiss francs, or about RMB 4.88 million. The Sea-Dweller series can be traced back to the cooperation between Rolex and French underwater engineering company Comex and the US military in the 1960s. In order to adapt to deep-sea saturation diving, Rolex added a new patented ‘helium exhaust valve’ to the side of the case based on the Ref. 5513 of the Water Ghost series, and then specifically Ref. 5514 for Comex. The ‘helium exhaust valve’ has also become the distinguishing point between the sea-dweller series and the water ghost series. Many people think that the helium exhaust valve is very high-tech. It can automatically adjust the pressure inside and outside the case to prevent the watch from being broken. In fact, the structure of the helium exhaust valve is very simple. Just a water-proof rubber ring, a short metal rod, and a spring leaf, the working principle is exactly the same as the pressure cooker valve used in the home. When the internal pressure of the case is high, the spring leaf deforms and drives the metal rod to protrude outward, and the high-pressure gas inside is released through the gap between the metal rod and the case. Once the internal and external pressure is balanced, the spring leaf returns to its original state, naturally driving the metal rod to retract, and the external moisture is isolated by the rubber ring. After further upgrades, the waterproof depth was increased from 200 meters to 500 meters for water ghosts, and began to mark the dial with ‘Sea-Dweller’, and the white font was labeled ‘Submariner water ghost’. ‘Single Red’. By this period, it still belongs to a small-scale experimental stage. ‘Sea-Dweller’ is also subordinate to ‘Submariner’. In 1977, 10 years later, Ref. 1665, which was officially released for sale, cancelled the design of the two-line font ‘Sea-Dweller’ and ‘Submariner 水鬼’ printed in red on the dial, only marked with white capital ‘Sea-Dweller.’ 1977 is also known as the Nether Envoy series in the narrow sense, separated from the Water Ghost series, a key year of its own. The Rolex Ref.1665 prototype sold this time belongs to the American diver Robert Palmer Bradley, who was working on a deep-sea submersible ‘Deepstar-4000’ designed by the famous marine explorer Jacques Cousteau on the East Coast of the United States and the Caribbean. The area conducts diving and studies marine geology and biology, which is affiliated with the Office of Oceanography of the United States Navy. In November 1968, Rolex presented this watch to Robert Palmer Bradley in honor of the 500th dive of the Deepstar-4000. At present, most of the original engraving on the back of the case has been lost, but it can be discerned to distinguish Bob’s name from the 11th. However, not all Sea-Dweller prototype watches have a ‘helium exhaust valve’, because it was still in the development and testing stage. Because these watches are prototypes and used for intense field testing, not many have survived over time. Researchers have now found 12 ‘Single Red’ Sea-Dweller sea dwellers, none of which have helium exhaust valves. At the same time, according to Jose Perez’s statistics, the current Rolex of Robert ‘1602913’ is the earliest known Sea-Dweller Ref. 1665.