Sea-Dweller 126603

Rolex Sea-Dweller 126603 (Two-Tone Black Dial)

The Rolex Sea-Dweller Ref. 126603 marks a historic first for the model line: the introduction of Rolesor, combining Oystersteel with 18K yellow gold for the very first time in Sea-Dweller history. Launched in 2023, this reference brings a touch of refinement to Rolex's legendary professional diving watch, originally designed for deep-sea saturation diving.

The watch features a robust 43 mm Oyster case, with a unidirectional rotatable bezel in 18K yellow gold fitted with a black Cerachrom ceramic insert, virtually scratchproof and resistant to fading from UV exposure. The black dial is equipped with Chromalight luminescent display, emitting a long-lasting blue glow for enhanced legibility in dark or underwater conditions, complemented by a date window at 3 o'clock magnified by the Cyclops lens.

A defining feature of the Sea-Dweller is the helium escape valve, located on the left side of the case, which automatically releases helium gas buildup during decompression after saturation diving. Combined with a screw-down Triplock crown, domed sapphire crystal, and solid caseback, the watch achieves an impressive water resistance of 1,220 meters (4,000 feet), maintaining the model's professional-grade diving credentials.

Powering the watch is the Rolex Calibre 3235, a fully in-house automatic movement. It operates at 28,800 vibrations per hour (4 Hz) with 31 jewels, delivering hours, minutes, seconds, and quickset date. The movement features the Chronergy escapement for greater efficiency and resistance to magnetic fields, a Parachrom hairspring, and Paraflex shock absorbers, providing a power reserve of approximately 70 hours. It is certified as a Superlative Chronometer, ensuring precision of −2/+2 seconds per day after casing.

The watch is fitted with the Oyster bracelet in Rolesor (Oystersteel center links, 18K yellow gold outer links), secured by an Oysterlock safety clasp featuring the Glidelock extension system, allowing micro-adjustments of up to 20 mm, ideal for wearing over a diving suit.

Key Specifications

• Reference: 126603

• Collection: Sea-Dweller

• Case Material: Oystersteel with 18K yellow gold (Rolesor)

• Bezel: Unidirectional rotatable, 18K yellow gold with black Cerachrom insert

• Diameter: 43 mm

• Thickness: approx. 14 mm

• Dial: Black with Chromalight luminescent markers

• Calibre: Rolex 3235, automatic, in-house

• Jewels: 31

• Frequency: 28,800 vph (4 Hz)

• Functions: Hours, minutes, seconds, date (quickset)

• Power Reserve: ~70 hours

• Precision: Superlative Chronometer (−2/+2 sec/day)

• Water Resistance: 1,220 meters (4,000 ft) / 122 ATM

• Special Feature: Helium escape valve

• Bracelet: Oyster Rolesor with Oysterlock clasp + Glidelock extension