Rolex Sea-Dweller 4000

From 2014 to 2017, the Sea-Dweller 4000 was one of Rolex's top-performing diving watches. Its 40-mm stainless steel case is water-resistant to 1,200 m, which translates to 4,000 ft, hence the watch's name. This watch has the reference number 116600. It is the successor to the Sea-Dweller ref. 16600, which the Swiss luxury watch manufacturer had replaced with the Sea-Dweller Deepsea only six years prior. The Deepsea is water-resistant to 3,900 m (390 bar, 12,795 ft). However, at 44 mm, it is not suited to every wrist, which is why Rolex decided to bring back the Sea-Dweller 4000 as an alternative professional model.

The Sea-Dweller 4000 is a professional tool for every diver. It features Rolex's especially secure Triplock crown, a helium escape valve for saturation diving, and a unidirectional bezel with a black ceramic inlay. The luminous material Chromalight coats its large applied indices and hands and causes them to glow bright blue in the dark, forming a nice contrast with the black dial. The chronometer-certified caliber 3135 ticks away inside the case and deviates by a maximum of +/- 2 seconds per day. It also provides the watch with its date display at 3 o'clock. Unlike its smaller relative, the Rolex Submariner, the Sea-Dweller 4000 has no cyclops lens.

Rolex retired the Sea-Dweller 4000 in 2017 and replaced it with the Sea-Dweller ref. 126600. This watch stands out with its larger, 43-mm case, red "Sea-Dweller" inscription on the dial, and cyclops lens over the date display.

The Sea-Dweller 4000 ref. 116600 has performed quite well in recent years. In July 2020, a never-worn edition demanded around 14,500 USD, while pre-owned pieces cost only marginally less.

Prices were already rising by the time Rolex announced they were retiring the model in 2017, having increased from 9,300 to 11,500 USD. As you can see, the Sea-Dweller has a promising future ahead, and is therefore a sound investment option.

The Sea-Dweller 4000 is water-resistant to 1,220 m (122 bar, 4,000 ft). Rolex crafts both its 40-mm case and three-piece link Oyster bracelet out of 904L stainless steel, a particularly durable and non-corrosive alloy known internally as "Oystersteel." The case is a single piece of solid steel and features a screw-down case back. Finally, scratch-resistant sapphire crystal protects the Sea-Dweller 4000's dial.

The crown's winding stem is a potential weak point in every water-resistant watch, as it's an additional opening in the case. To prevent water from leaking in through the crown, Rolex equips the Sea-Dweller 4000 with a so-called Triplock crown system. This mechanism uses four rubber o-ring gaskets to prevent water and dirt from finding their way into the case. The crown remains screwed into the case in its normal position; it's only unscrewed to set or wind the watch.

Helium Escape Valve

One of the Sea-Dweller's defining features is its helium escape valve. This is also true of the Sea-Dweller 4000. The valve is an essential feature for saturation diving, as it prevents potential damage during decompression. Divers who work at great depths breathe a mixture of oxygen and helium. However, helium molecules are so small that they easily slip past the watch's various seals and settle in the case. As pressure subsides during decompression, these molecules expand. If they can't escape the case quickly enough, they can cause the watch's crystal to pop out. Rolex solved this problem by inventing the escape valve. While it functions manually on some watches, it works automatically on the Sea-Dweller 4000.

Ceramic Meets Platinum

Like any good diving watch, the Sea-Dweller 4000 comes with a unidirectional diving bezel. Thanks to its ribbed edge, divers can easily operate it with gloves on. Rolex outfits the bezel with a black Cerachrom inlay with a 60-minute scale. The Genevan manufacturer finishes the scale's numerals and minutes with a platinum PVD coating.

The luminous material Chromalight covers the hands, indices, and the bezel zero marker. It shines bright blue in the dark, and Rolex claims it also glows longer than competing materials. During the day, it appears white and creates a contrast against the black dial.

The in-house caliber 3135 is the beating heart of the Sea-Dweller 4000. It has a power reserve of 48 hours and ticks at a frequency of 4 Hz or 28,800 vibrations per hour. Experts praise the 3135 for its exceptional durability and precision. It has passed not only the tests of the Official Swiss Chronometer Testing Institute (COSC) but also Rolex's more rigorous internal tests, thus qualifying as a "Superlative Chronometer." This distinction means the movement has a maximum daily deviation of only +/- 2 seconds from the reference time.

A diving watch's band should be easy to adjust, as it needs to fit over a wetsuit. Therefore, the Sea-Dweller features both Glidelock and Fliplock technology. Fliplock extension links enable the wearer to lengthen the bracelet significantly.

On the other hand, Glidelock technology allows for more fine adjustment by releasing the last link from the clasp and fixing it in a new position.