The reference 16666 is not a real Rolex number. It shows up in replica listings as a typo for the Sea-Dweller 16660, the 40mm dive watch Rolex built from 1978 to 1989, or for the 16600 that followed it. So a "fake Rolex Sea-Dweller 16666" is, in practice, a copy of one of those two watches.
Which Real Reference Matches "16666"?
Rolex has never stamped 16666 on a case back. Two references sit close enough to explain the mix-up, and both serve as common bases for replica builds.
Sea-Dweller 16660 ("Triple Six")
Rolex launched the 16660 in 1978 and kept it in the catalog through 1989. It carried a 1,220 m depth rating, a thicker sapphire crystal, and a helium escape valve on the left case flank. Collectors call it the "Triple Six" for the repeated reference digits.
Sea-Dweller 16600
The 16600 replaced the 16660 in 1989 and ran until 2009. It shares the 40mm case and the 1,220 m rating but uses the Caliber 3135 with a quickset date. Most replica Sea-Dwellers sold today copy this reference because parts are easy to source.
Why the Number Gets Mistyped
- The digits repeat: 16660, 16600, and 1665 look alike on a phone screen.
- Marketplace titles get copied from listing to listing, so one error spreads.
- Some sellers invent numbers to dodge brand takedown requests.
What Separates a Good Replica From a Cheap One
Replica quality comes down to proportions and finishing. A $90 watch and a $450 watch can look the same in a thumbnail and feel nothing alike in your hand.
Case and Bezel
The 16660 case measures 40mm across, about 15mm thick, with 20mm lugs. Good copies keep the lug shape and the slight crown-guard bevel. Cheap cases run thick and slab-sided, and the bezel insert paint sits on top of the numbers instead of inside them.
Dial, Hands, and Lume
Older 16660 dials use tritium markers that age to a warm tone, while later ones use Super-LumiNova. Replicas often use one dial for both eras. Check the date window size, the font on the depth rating, and whether the lume glows green or blue.
Helium Escape Valve
The valve on the case side is a real feature, not a sticker. On the 16660 it is a fixed valve with a hex shape. Cheap replicas stamp a flat circle there or fake it with a screw head, and a working valve is rare even on top-tier copies.
Bracelet and Clasp
The 93150 Oyster bracelet with a flip-lock clasp is the correct pair for the 16660. Look for solid end links, a stamped crown logo, and a clasp that closes with a firm click. Hollow, rattling links point to an entry-level build.
Movement
- Entry: 21-jewel Chinese automatic, no hacking, loud rotor.
- Mid: Seagull or Hangzhou clone of the ETA 2824, hacking, 28,800 vph.
- Top: Swiss ETA 2824 or a decorated clone of the Rolex 3135 with a blue hairspring (cosmetic only).
Replica Grades and Typical Prices
Price tracks the movement and the case work, not the banner on the website. Expect about $80 to $150 for entry builds, $200 to $350 for mid-grade, and $400 and up for top-tier copies with Swiss movements.
- Under $150: stamped parts, painted bezel, short service life.
- $200 to $350: machined case, sapphire crystal, ETA-style movement.
- $400 and up: Swiss movement, closer case geometry, better bracelet.
Quick Checks Before You Pay
- Ask for a photo of the case side to confirm the helium valve is raised, not engraved.
- Request a video of the second hand. A sweep with 8 beats per second means an ETA-style movement; 6 beats means a cheap 21,600 vph unit.
- Measure the lug width. It should be 20mm on a 16660 or 16600.
- Check the crown: roughly 7mm, Triplock style, with three dots or a line.
- Get the bracelet reference and clasp code in writing before you send money.
Legal and Practical Notes
Replica watches are counterfeits. Selling them is illegal in the US, and customs can seize shipments at the border. Buying for personal use sits in a gray area that varies by state.
Do not take a copy diving. Gaskets on replica cases are not pressure tested to 1,220 m, and the escape valve often does not seal at all. Water contact is a risk, not a feature.
FAQ
Is the Rolex Sea-Dweller 16666 a real reference?
No. Rolex never made a 16666. The number is a typo for the 16660 or the 16600, both real Sea-Dweller references.
What movement should a good replica Sea-Dweller use?
A Swiss ETA 2824 or a high-grade clone with a smooth sweep and hacking seconds. Chinese 21-jewel movements sit on the low rung.
How much does a fake Sea-Dweller 16660 cost?
Most run from about $80 for a basic copy to $500 or more for a top-tier build with a Swiss movement. Price follows the movement, case machining, and bracelet quality.
Can a replica Sea-Dweller survive 1,220 m?
No. Replicas are not pressure tested, and their gaskets and valve seals fail far above recreational dive depths.
Picking the Right One
Start with the reference. A 16660 copy needs a fixed hex helium valve and a matte dial; a 16600 copy needs the gloss dial and the 3135-style movement. Match the case to 40mm and the bracelet to the 93150, then decide how much you want to spend on the movement.