The short answer
A replica Rolex 16660 can be genuinely good, and it is one of the easier vintage Rolex models to copy well. The "Triple Six" Sea-Dweller has a plain black dial, no cyclops over the date, a thick steel case, and simple printed text. There is no magnifier to align and no precious metal finish to imitate. A mid-tier or high-tier replica can sit close to the original on the wrist. Budget versions still fail. The cheapest 16660 replicas miss on case thickness, bezel insert font, lume color, and the helium escape valve. Learn five details and you can sort a good one from a bad one in about a minute.
What the reference actually is
Rolex built the Sea-Dweller 16660 from 1978 into the late 1980s. It replaced the 1665 and brought a sapphire crystal, a larger helium escape valve, and the Caliber 3035 with a quick-set date. The case is 40 mm across and about 15 mm thick, rated to 1,220 m (4,000 ft). The dial came in two main styles: early matte with painted markers, and later glossy with white gold surrounds. No Sea-Dweller of this era has a magnifier on the crystal. If the replica in front of you has one, the factory copied a Submariner instead.
Before you shop
- Decide which dial style you want, matte or glossy, and stick to it.
- Set a budget tier so you do not compare a $90 watch against a $600 watch.
- Know the bracelet: an Oyster 93150 style with a flip-lock clasp and a dive extension.
- Plan to have any automatic watch checked by a local watchmaker on arrival.
How to check a replica 16660 before you buy
- Ask the seller to measure the case width and thickness with calipers, and expect roughly 40 mm by 15 mm. A 12 mm thick case is a giveaway that you are looking at a slim Submariner case.
- Check the crystal for a cyclops magnifier. The 16660 has none, so a magnifier means the wrong model.
- Inspect the helium escape valve on the left case flank. It should sit inside a raised housing with a visible collar, not a shallow sticker or a flat bump.
- Read the depth rating on the dial and confirm it matches the 16660 spec of 1,220 m and 4,000 ft, rather than the older 610 m marking used on the 1665.
- Compare the bezel insert against photos of an original black insert, watching the weight of the numerals and the position of the pip at 12.
- Look at the date window straight on. With no magnifier, a crooked or off-center date wheel has nowhere to hide.
- Time the seconds hand over 60 seconds. A Caliber 3035 based movement should tick 8 times per second, which reads as a smooth sweep rather than a stutter.
- Request daylight photos of the case flanks, the lug holes, and the crown, then check that the crown is a Triplock style with the correct 7 mm profile.
What separates the tiers
Budget replicas in the $80 to $150 range usually run a low-beat movement, use a thin case, and print the dial text too large. Mid-tier pieces in the $200 to $400 range often fix the case and crystal but still use a generic Submariner bezel insert and pale green lume. High-tier replicas above roughly $500 typically get the case profile, the valve, the insert font, and the dial printing close to correct, and they run a Swiss ETA 2836 or a decent 3035 clone. That last group is where the answer to your question changes from "no" to "yes, with caveats."
Verdict
The 16660 is a strong candidate for a replica because its design is plain and its giveaways are few. Buy from the mid tier or above, verify the crystal, the valve, the depth rating, and the sweep, and you get a watch that reads correctly across a table. Buy at the bottom and the thin case and oversized dial text will announce themselves from across the room.