Strapped to the outside of James Cameron’s submersible, an experimental Deepsea Challenge watch reached the floor of the Mariana Trench in 2012. Two years later Rolex gave the production Deepsea a dial that retraces that descent, and collectors have been chasing it ever since.

Presents itself in mint condition with little to no signs of wear. Graded from bright blue at the top to full black at the bottom, the dial recreates the way daylight surrenders on the way down. Framed by a black Cerachrom insert with platinum-filled numerals and graduations, the bezel turns one way only and holds its setting through a dive. Engineered around the Ringlock System, the 44mm Oystersteel case carries a domed sapphire crystal and a grade 5 titanium back built to take extreme pressure. Assembled from three-piece links with brushed surfaces and polished sides, the Oyster bracelet closes on an Oysterlock safety clasp with Glidelock adjustment and a folding Fliplock extension for a wetsuit.

Functions include hours, minutes, seconds, and date. Unscrew the Triplock winding crown at 3 o’clock and turn about 40 times in the first position to wake the self-winding Calibre 3135. Pull to the second position for rapid date setting and set to yesterday’s date, then pull to the third position to stop the seconds hand, walk the hands past 12 to today’s date and on to the correct time. Screw the crown back down for 3,900 metres of water resistance, and the helium escape valve at 9 o’clock manages decompression on its own. Roughly 48 hours of power reserve carries it through a weekend off the wrist, and the Chromalight display glows blue in low light.

Few watches carry a story you can point at on the dial. If the piece your collection is missing is the one that actually went to the bottom of the ocean, a short message is all it takes to start the conversation.