The Rolex Explorer reference 6610 is one of the early Explorer models, and a favorite among collectors. Originally introduced in 1959, it replaced the reference 6150. On the outside, the two watches appear nearly identical. However, this particular reference is identified by its flatter back. This is due to the watch’s use of the caliber 1030 mechanical movement with 25 jewels over the reference 6150’s larger movement, which needed a bubble-back case to accommodate it.
photo courtesy of Bob’s Watches
This reference gave consumers the Explorer in its most recognizable form. Made of stainless steel, the water-resistant case measures about 36 millimeters in diameter. Being an earlier Rolex model, the case is waterproof but only up to 50 meters. It accomplishes this through Rolex Oyster technology, which utilizes a screw down crown and caseback. All original 6610 dials and hands are classified as “gilt”, marked by gold text (with just a few exceptions), chapter ring, and Mercedes hands. Aside from the rare albino dial, the 6610 dial is typically black, finished with a lacquer coating, and sports luminous baton markers and Arabic numbers. Pulling the look together was a stainless steel Rolex Oyster riveted bracelet with stamped clasp.
Rolex Movement Explorer 6610 — photo courtesy of Bob’s Watches
The 6610 was produced for about five years before it was replaced with reference 1016 in 1963. Though quite similar in appearance, the reference 1016 uses the caliber 1560 movement and has an increased waterproof depth from 50 meters to 100 meters, as the Oyster case saw continued refinement. What’s more, the 1016 brought on the full transition to tritium for luminous material, versus the highly radioactive radium of the 6610. Don’t touch that dial!
Because this reference is an early Explorer model and only produced for a short time, they are exceedingly rare. It’s speculated that in the five years of production, the amount of 6610s made is merely a fraction compared to the 1016. Furthermore, since the 6610 is an older reference, chances are higher that parts would be replaced during service, especially dials aggressively aged by paint defects and radium degradation. What this leads to is even smaller numbers of original and legitimate 6610 examples available on the market.
Photo courtesy of Bob’s Watches
As you can probably guess, 6610 prices not only have a wide range, but are getting higher and higher in general. Expect a good 6610 to go for at least $10,000, maybe close to $15,000 in very good condition. Of course, if you find a rare albino dial under the crystal, you can pretty much name your price. If you are looking for a unique and valuable collector’s piece to add to your Rolex collection, or to simply serve as your one “good” watch, it’s hard to go wrong choosing a vintage and original Rolex Explorer reference 6610.
Editor’s Note: Photos and content courtesy of Bob’s Watches. Thanks to Chris Foerster and Paul Altieri of Bob’s Watches for the access to this gorgeous example.
by 
Tom nosker
One of the coolest watches with great history!