Quick answer
A fake Rolex Sea-Dweller 16600 is a copy of a 40 mm dive watch Rolex built from 1989 to 2008. The genuine reference rates to 1,220 m (4,000 ft), runs the Caliber 3135, and carries a helium escape valve at 9 o'clock. The crystal is flat sapphire with no cyclops. Most replicas match the outline. Fewer match the movement, the valve, or the depth rating.
Genuine 16600 specs
- Reference: 16600, produced 1989 to 2008
- Case: 40 mm Oystersteel, about 14.8 mm thick
- Lug width: 20 mm
- Water resistance: 1,220 m / 4,000 ft
- Movement: Rolex Caliber 3135, 31 jewels, 28,800 vph, about 48 hours of power reserve
- Crystal: flat sapphire, no magnifier
- Bezel: unidirectional, 60-minute, black insert with a luminous pip
- Bracelet: Oyster 93160 with Fliplock clasp and divers extension
- Dial: black, tritium to about 1998, then Super-LumiNova
Where replicas differ
Case and thickness
Genuine cases measure about 14.8 mm thick. Many replicas run 15.5 mm to 16 mm because the clone movement sits taller inside the case. Check the lug tips. Genuine lugs taper and the top edges carry a chamfer. Replica lugs read thick at the tips.
Crystal and bezel
The 16600 never had a cyclops. Replicas that add one are wrong on sight. On the bezel, the genuine pip is a raised luminous dot set in a metal ring. Replica pips sit flat and yellow within a year.
Movement
Early replicas used an ETA 2824-2 or 2836-2. Those change the crown position and the hand stack height. Later replicas use a clone 3135 sold as SA3135, SH3135, or VR3135. A real 3135 beats 8 times per second and holds about 48 hours. Clone builds vary. Some keep time. Some lose 20 seconds a day.
Helium escape valve
The genuine valve sits on the left flank at 9 o'clock and works. Many replica valves are decorative caps or glued inserts. Turning one can crack the case.
Water resistance
The genuine rating is 1,220 m. Replicas ship with untested gaskets. Treat a replica as 0 m until a watchmaker runs a pressure test.
Dial text
Tritium dials to about 1998 read "T Swiss T" or "Swiss T<25" at 6 o'clock. Later dials read "Swiss Made". The genuine "Sea-Dweller" line uses thin, evenly spaced type. Replica printing is thicker with cramped spacing.
What to check first
- Measure case thickness with calipers.
- Look for a cyclops. There should not be one.
- Count the beat rate at 8 per second.
- Inspect the helium valve for a glued cap.
- Read the dial text at 6 o'clock for the tritium marking.
Prices
Replica 16600 builds list from about $300 to $600. Clone-3135 versions sit at the top of that range. Modded examples run higher. Genuine 16600 sales listed between roughly $8,000 and $12,000 on the secondary market in 2024. Verify current listings. Values move.
Legal note
In the United States, selling a counterfeit watch as genuine is a federal crime under 18 U.S.C. § 2320. Buying a replica is a different matter, but customs can seize shipments. No replica passes authentication by Rolex or by a trained dealer.