Rolex · Sea-Dweller and Rolex Deepsea
Rolex 126600 vs Rolex 136660
6 published specifications differ between these two, and 9 are identical. Every figure below is what the manufacturer states for that reference; nothing is inferred from the other watch.
What differs
| Specification | ||
|---|---|---|
| Case | Oyster, 43 mm, Oystersteel. Monobloc middle case, screw-down case back and winding crown | Oyster, 44 mm, Oystersteel. Monobloc middle case, screw-down case back and winding crown. Rolex Ringlock System case architecture with helium escape valve |
| Diameter | 43 mm | 44 mm |
| Water resistance | Waterproof to 1,220 metres / 4,000 feet, helium escape valve | Waterproof to 3,900 metres / 12,800 feet, helium escape valve |
| Crystal | Scratch-resistant sapphire, Cyclops lens over the date | Domed, 5.5 mm-thick scratch-resistant sapphire |
| Dial | Intense black, with highly legible Chromalight display with long-lasting blue luminescence | D-blue, with highly legible Chromalight display with long-lasting blue luminescence |
| Movement notes | Precision −2/+2 sec/day after casing. Instantaneous date with rapid setting and stop-seconds. | Precision −2/+2 sec/day after casing. Instantaneous date with rapid setting and stop-seconds. Paramagnetic blue Parachrom hairspring with Paraflex shock absorbers. |
What is identical
Worth knowing as much as the differences: these are the specifications you cannot use to tell the two apart.
- Bezel
- Unidirectional rotatable 60-minute graduated, scratch-resistant Cerachrom insert in black ceramic, numerals and graduations coated in platinum
- Case back
- Screw-down
- Crown
- Screw-down, Triplock triple waterproofness system
- Bracelet
- Oyster, three-piece solid links, Oystersteel
- Clasp
- Folding Oysterlock safety clasp with Rolex Glidelock extension system
- Calibre
- Calibre 3235, Manufacture Rolex
- Movement
- Perpetual, mechanical, self-winding; bidirectional self-winding via Perpetual rotor
- Power reserve
- Approximately 70 hours
- Certification
- Superlative Chronometer (official chronometer certification + Rolex certification after casing)
What the differences cost you
Each note below follows from the published figures in the tables above — what they mean for intake, for a listing, and for the handover. Nothing here estimates a price or a margin.
Do not describe these the same way
3,900 metres on the 136660 against 1,220 on the 126600 — not a variation on the same watch but a different class of one, built around a case and crystal designed for depth. Expect different buyers, different questions, and a different service conversation. Never carry the 136660's rating into the 126600's listing.
What to check on each
126600
- Locate and inspect the helium escape valve on the case flank. It is a functional gas-release component on a saturation-rated watch, and a damaged or previously opened valve is a sealing question.
- Confirm the Cyclops is present and correctly bonded. This generation of Sea-Dweller carries one where earlier ones did not, so its presence is part of identifying the reference rather than an option.
- Check the platinum-coated graduations on the Cerachrom insert for even fill, the same test that applies on the Submariner.
136660
- Locate the helium escape valve on the case side and confirm it is present and undamaged. It is a functional valve, not a decoration, and it appears on no other Rolex documented here.
- Examine the domed crystal's edge under raking light. Rolex specifies it at 5.5 mm thick, which makes it the tallest and most exposed sapphire in this corpus, and sapphire chips rather than scratching.
- Run the Glidelock extension out and back through its full travel. It is a toothed adjustment inside the clasp, it is the mechanism most used on a dive bracelet, and a worn one slips under load.
Sources
- Rolex official product page for reference 126600 (Sea-Dweller; Oyster 43 mm; Oystersteel) - Model case: Oyster; 43 mm; Oystersteel; Oyster architecture: monobloc middle case; screw-down case back and winding crown; Diameter: 43 mm; Material: Oystersteel; Bezel: unidirectional rotatable 60-minute graduated with scratch-resistant Cerachrom insert in black ceramic and numerals and graduations coated in platinum; Winding crown: screw-down with Triplock triple waterproofness system; Crystal: scratch-resistant sapphire with Cyclops lens over the date; Water resistance: waterproof to 1220 metres / 4000 feet with helium escape valve; Movement: perpetual; mechanical; self-winding; Calibre: 3235; Manufacture Rolex; Precision: -2/+2 sec/day after casing; Functions: centre hour; minute and seconds hands; instantaneous date with rapid setting; stop-seconds; Oscillator: paramagnetic blue Parachrom hairspring with Paraflex shock absorbers; Winding: bidirectional self-winding via Perpetual rotor; Power reserve: approximately 70 hours; Bracelet: Oyster; three-piece solid links; Oystersteel; Clasp: folding Oysterlock safety clasp with Rolex Glidelock extension system; Dial: intense black with Chromalight display; Certification: Superlative Chronometer — retrieved 2026-09-22
- Rolex official product page for reference 136660 (Rolex Deepsea; Oyster 44 mm; Oystersteel) - Model case: Oyster; 44 mm; Oystersteel; Oyster architecture: monobloc middle case; screw-down case back and winding crown; Rolex Ringlock System case architecture with Helium escape valve; Diameter: 44 mm; Material: Oystersteel; Bezel: unidirectional rotatable 60-minute graduated; scratch-resistant Cerachrom insert in black ceramic; numerals and graduations coated in platinum; Winding crown: screw-down; Triplock triple waterproofness system; Crystal: domed; 5.5 mm-thick scratch-resistant sapphire; Water resistance: waterproof to 3,900 metres / 12,800 feet; helium escape valve; Movement: perpetual; mechanical; self-winding; Calibre: 3235; Manufacture Rolex; Precision: -2/+2 sec/day after casing; Functions: centre hour; minute and seconds hands; instantaneous date with rapid setting; stop-seconds; Oscillator: paramagnetic blue Parachrom hairspring; high-performance Paraflex shock absorbers; Winding: bidirectional self-winding via Perpetual rotor; Power reserve: approximately 70 hours; Bracelet: Oyster; three-piece solid links; Oystersteel; Clasp: folding Oysterlock safety clasp with Rolex Glidelock extension system; Dial: D-blue with highly legible Chromalight display; Certification: Superlative Chronometer — retrieved 2026-09-23
Not affiliated with Rolex. Specifications are read from each manufacturer's own published documentation on the dates shown and may change; the manufacturer's current documentation governs.