The Rolex Explorer II 16570: The Best-Value Rolex GMT

My first Rolex was an Explorer II 216570 with black dial and I absolutely loved that watch. It was rarer than the GMT-Master II or Submariner, and didn’t have the ceramic bezel, which I found to be a little too glossy and “luxe” for what I was looking for in a watch at the time. I kept and wore the heck out of that watch for almost six years until I just felt like it didn’t speak to me anymore. The 42mm wide “Maxi” case seemed too big and the big, thick hour and minutes hands just began to bug me. I can’t explain why I was so dead set on the 216570 rather than the older 16570 at the time but I can certainly say that now, in 2025, the Rolex Explorer II 16570 is not just my preferred iteration of the modern spelunking watch, but an all-timer from Rolex.

I’ve started to refer to the 16570 as a “Forever Rolex” because it ticks all the boxes — size, reliability, dual-time functionality, and discrete aesthetics — all while remaining one of the few Rolexes that isn’t immediately recognizable to every casual observer. Let’s take a look at why I’m such a big fan of this old-school Rolex.

Case and Specs: The Other Rolex GMT

Measuring 40mm wide and 12.2mm thick with a 47mm lug-to-lug height, the 16570 is an eminently wearable Rolex. And while this is very obviously a sport/tool watch, these proportions make for a very versatile and subdued piece. No, there isn’t a rotating bezel with a nickname-ready color combo here. Rather, there is a demure, fixed 24-hour bezel finished with some nice brushing that will definitely get scratched at one point or another. You will survive this.

Originally designed as a spelunking (aka cave diving) watch, the aesthetic of the original Explorer II mellowed out quite a bit by the time we got to the 16570. One of the signature calling cards of this collection has been the option of the now-beloved white (aka "polar") dial option in addition to the classic black dial. Honestly, I really do love both of them even though I’d give the polar dial an extra point or two just for how unusual it is.

And, of course, there is the incalculable appeal of being a true travel watch. With a jumping, independently adjustable hour hand and that classic thin red GMT hand with triangular tip, the 16750 is a legitimate GMT. Sure, it’s only two time zones but you do get the added benefit of an AM/PM indicator if the GMT hand is synced with local time. Finally, there is the cyclops date window that some people love to hate but is inarguably very easy to read and ultimately useful.

The Movements

The Rolex Explorer II 16570 was outfitted with either the Calibre 3185 or 3186. These were the same movements that were found in the GMT-Master watches, though those would admittedly get the updated movement a year or two before the Explorer II. The Caliber 3185 was an updated version of the older 3085, which was Rolex’s first movement with an independently adjustable GMT hand. Like the 3085, the 3185 operates at 4 Hz and has a 48-hour power reserve but has 31 jewels (compared to 27) and was thinner at 6.45mm (compared to 7.2mm). Later models of the 16750 were equipped with the Caliber 3186, which had improved shock and temperature resistance due to the Parachrom hairspring and a minor power-reserve update from 48 to 50 hours.

A Rolex Explorer II 16750 For Everyone

Another reason I adore this reference is that its long production life means there are options for just about everyone. Someone looking for the most mainstream, no-fuss 16570 should opt for the later models with the etched rehaut and Caliber 3186 movement. The pickier collector can try and hunt for some of the rarer early or transition models while those who love to change a strap or bracelet have plenty of options with drilled lugs.

The 16570 debuted in 1989 and was produced all the way through 2010, giving it a very long two-decade lifespan. Aesthetically very similar to the preceding 16550, there were some major upgrades here, like the addition of the then-new Caliber 3185 movement followed by the Caliber 3186 part-way through its production. Considering the significant length of time this reference was produced, there are a few variants within the collection which shouldn’t surprise anyone, because Rolex has long been a pioneer of iterating within reference lines. With this in mind, you’ll find 16570 models using the older Caliber 3185 as well as the updated Caliber 3186.

Also, there were several developments in materials, case manufacturing, and counterfeit-prevention measures during these two decades that help to sort out the various Explorer II 16570 watches produced. Starting with lume, the models produced up until just around 1995 had tritium, models from the mid-nineties to the late nineties used Luminova, and the final batch used SuperLumiNova. And then there is the move from cases with drilled holes on the lugs to no-hole cases, which is a transition that took between 2003-2004 to complete. So, it is obviously pretty easy to get these mixed up. Fortunately, it’s not too difficult to break the Rolex Explorer II 16570 into four easy groups.

The first iteration ran from 1989 to about 1997 and is easily denoted by the “SWISS – T<25” text at 6 o’clock indicating the tritium lume, and also by its drilled lugs, the 3185 movement, and the not-so-great but still hard-to-find pre-update bracelet with hollow end links. These are models you need to be particularly careful with due to the prevalence of hands that are not original (likely due to servicing during which the tritium was replaced with Super-LumiNova). So, look out for patina on the hands and make sure the patina on the hands and hour indices doesn’t look the same, because they do age a little differently. You’ll likely encounter the phrase“Chicchi di Mais” here, which is Italian for “corn kernels” and refers to a particularly collectible dial where the tritium is a unique yellow.

The second iteration is pretty rare. These were produced in 1998 and 1999 and had LumiNova replace the tritium lume but it’s the “Swiss Only” designation that makes these collectible. While basically every Explorer II from 1999 on had “Swiss Made” on the dial, these models just read “Swiss” at 6 o’clock. The second iteration also debuted the new bracelet with flip-lock clasp. The third iteration upgraded to Super-LumiNova and began to have the “Swiss Made” text at 6 o’clock. This iteration began in 1999 and used drilled lugs until about 2003 when they began to roll out the no-holes case.

Finally, the fourth and last iteration of the 16570 began to be rolled out around 2005. The biggest update here is the updated Caliber 3186 movement, which was a welcome improvement over the outgoing 3185, which notoriously had a wobbly hour hand. This new movement also introduced a Parachrom hairspring while the 50-hour power reserve remained unchanged. This is really when the “modern luxury” era was coming into its own as these models got the laser-etched “ROLEX” repeating text in the rehaut.

A Modern 40mm Rolex Explorer II?

So, I’m sure it’s not too difficult to figure out what my obvious ideal current production Explorer II would be. While I can’t claim to be sure the current Caliber 3285 would fit into a 40mm case, it is the same movement used in the current GMT-Master II, which happens to be 40mm wide. An Explorer II with the benefits of a 70-hour power reserve, Parallax shock system, and Parachrom balance spring all in a 40mm wide case? Without a hint of exaggeration, I would pay retail price  ($10,050) for that/get on the waitlist as soon it was announced. You can learn more about the Explorer II over at rolex.com.