Review: The Rolex Explorer II ref. 16570

Strangely, even though Rolex’s Explorer II is steaming towards its 50^th birthday, we are still only into its fourth individual reference.

It is one of those little facts about the series that seems to underline its long held status as being among the ‘forgotten Rolex’.

In general, the watchmaker’s offerings tend to fall into one of two categories; there are the out-and-out icons—the Submariner, Daytona, GMT-Master, etc. And then there are the second tier, the ones that have always remained on the periphery compared to their more recognizable stable mates. They are the models that never received the same level of continuous development, whether in design and technology, or in graduating to precious metal cases.

The Explorer II falls into the latter group, sitting alongside others such as the Milgauss, the Air-King and even the original Explorer. They too seem to have been held back in their progression, with some iterations, such as the ref. 1019 Milgauss or the Air-King ref. 5500, going along unchanged for 30 or 40-years.

As a result, these under-the-radar pieces garner a different kind of fandom, tending to be loved most by the ardent purists; those who yearn for the days when Rolex still made full-blooded tool watches. They are the cult classics in the collection, and the ref. 16570 Explorer II is a prime example.

It also enjoyed a protracted run, debuting in 1989 and being replaced some 22-years later by the current incarnation in 2011. However, it did go through at least one notable change during all that time, with its movement being upgraded towards the end of its production.

In addition, it holds the distinction of being the most affordable of the breed, with the number of models built over its two decades ensuring prices on the preowned market are kept very reasonable.

Below, we take a closer look at this superb watch.

Rolex Explorer II ref. 16570 Metal and Bezels

Always true to its roots, the ref. 16570 is an exclusively stainless steel creation, as is every version of the Explorer II ever made.

Back when the series was introduced, Rolex was still using the same 316L steel employed by the vast majority of the luxury watch industry today, before it advanced, at enormous expense, to the 904L of the current catalog.

While 904L is supposedly the more hard wearing of the two metals, 316L is still a massively tough material, and has the added bonus of a lower nickel content, something appreciated by those with an allergy to it.

As for the bezel, unlike the Submariner or the GMT-Master II (a piece that shares many similarities with the Explorer II that we will get to a bit later) the surround on the ref. 16570 is non-rotatable.

The model was originally intended to be used in cave exploration or on expeditions to the poles, two places where there is either no light, or in the case of summertime in the frozen tundra’s of the Arctic and Antarctic, too much. Losing track of day and night when the sun never rises or sets is pretty much guaranteed, so the bezel is engraved with a 24-hour scale and the watch uses an additional hour hand, geared to run at half the speed of the main hour hand, to point out the reference time.

When the first Explorer II emerged in 1971, those two hands were linked, and with the surround fixed in position, it meant it was little more than an AM/PM indicator. As the internal mechanics improved over the years, it has progressed to have independently adjustable hour hands, and is now a genuine GMT watch.

Rolex Explorer II ref. 16570 Movements

As we mentioned above, the Explorer II and GMT-Master II are very similar watches. In fact, putting their aesthetics and bezels aside, they are essentially pretty much identical.

For most of their respective lives, the two have shared not only a case but also the movement inside it. It is only with the very latest versions of each that the tie has been broken, with the GMT earning a promotion to Rolex’s next wave Cal. 32XX series of calibers, something the Explorer II will most likely gain in 2022 when it reaches its half century.

The ref. 16570 started life in 1989 with the Cal. 3185, which was also being used inside the GMT-Master II of the era, the ref. 16710.

It was the replacement for the fairly short-lived Cal. 3085, the first movement to unlink the pair of hour hands on the two model lines.

The distinctions between the Cal. 3085 and Cal. 3185 are slight, with the most substantial change being in physical size. Where the older mechanism stood some 7.20mm in height (meaning the cases they went in to had to be correspondingly larger—which is why the first of the GMT-Master II models is nicknamed the Fat Lady) the Cal. 3185 slimmed down to just 6.45mm. In addition, the power reserve increased from 42 to 50 hours.

Neither caliber had a Quickset date function, that feature having to be sacrificed for the independent hour hands. However they did have the ability to move the date numeral forwards or backwards with the jumping main hour hand, which shot around the dial by five or six hours with one turn of the winding crown, pulled out to its second position.

In all, the Cal. 3185 was a fine movement, ticking away at 28,800vph inside the ref. 16570 from 1989 until 2006. It was then replaced with the Cal. 3186, another engine with far more similarities than differences.

Its most significant steps forward consisted of an improved self-winding module, which actually increased its height again, coming in at 6.80mm. But more importantly it was fitted with Rolex’s Parachrom Bleu hairspring. Forged from an alloy of the brand’s own devising—a mix of niobium and zirconium—the combination of the two metals leaves the Parachrom hairspring completely antimagnetic and virtually unaffected by temperature changes. Its shock resistance is also reportedly 10 times greater than the Nivarox spring used previously.

It has been a major development for Rolex and has been rolled out onto every movement they now make.

Strangely, the hour hand with the Cal. 3186 was even livelier, now jumping eight hours with every revolution of the crown.

The manufacture’s Cal. 31XX series of calibers, taking the Cal. 3135 as their base, were massively successful, enjoying long service inside their respective watches. Exemplified by not only their unfailing accuracy (all easily passing COSC chronometer testing) but also their robustness, they were all no-nonsense workhorses that just kept on going no matter the level of harsh treatment.

Rolex Explorer II ref. 16570 Dials

Unlike many other models in the Rolex canon, from either the Classic or Professional Collections, the Explorer II has very little choice in dial color.

Essentially, you can have one of two; black or white.

As you would expect, what with them being complete opposites, each dial imparts a definite personality all its own on the watch.

The white, or Polar, dials are bright and crisp, and also something of a rarity. There just aren’t that many white dial Rolex’s in the catalog, and the Explorer II has garnered itself an enthusiastic fan base for precisely that reason. It is the more conspicuous of the two versions, catching the eye beautifully and giving the whole thing a fresh aspect. The simple dot hour markers are edged in black, as is the handset, to help with legibility, and they stand out perfectly against the background.

The black dial is far more understated and stealthy, and offers great contrast for easy readability. Here, the indexes and main hands are surrounded in white gold, a material that doesn’t tarnish as the steel used in older models was prone to do over time.

One specific point of interest with this watch has always been its extra 24-hour hand. The very first reference of the Explorer II, the ref. 1655 (sometimes known as the Steve McQueen) introduced what became known as the ‘Freccione’. The name meaning ‘arrow’ in Italian, it was a bright orange GMT hand which was especially prominent and popular among the watch’s admirers. That hand was replaced during the second and third generations (with the ref. 16570 being the latter) and those versions used the same style as the GMT-Masters. It is a long, thin hand topped with a small triangle and painted bright red. Not as striking as the Freccione perhaps, but still a detail loved by devotees.

With the ref. 16570 remaining in production for so long, it went through that period in its history when Rolex was changing the type of luminescence on its dials on a semi-regular basis.

For the first 10-years or so, the company was still using tritium, a radioactive (at a very low level) material, that had taken over from the former radium (which was far more dangerous). The models with this lume can be identified by the ‘SWISS T<25’ script on the very bottom lip of the dial, below the six o’clock index.

In the late 90s, they made the switch, briefly, to Luminova. Completely non-radioactive, it is what is known as a photoluminescent substance, in that it doesn’t produce the light itself, but rather has to be ‘charged’ by sunlight in order to glow. These dials are marked ‘SWISS’.

Finally, in 2000, Rolex brought in Superluminova, basically the same as Luminova but produced by a Swiss manufacturer. These are labeled ‘SWISS MADE’.

And one other discrepancy you might notice with later pieces; in the mid-2000s, as an anti-counterfeiting measure, the brand started engraving the rehaut, the inner edge between dial and crystal, with a repeated Rolex signature around the entire perimeter. As well as deterring forgers, it makes for a handy guide in estimating the date of manufacture of different models.

Rolex Explorer II ref. 16570 Bracelets

As you might expect of an all-out tool watch, the Explorer II was only ever issued on that sportiest of bracelets, the three-flat link Oyster.

However, like the luminescence, the bracelets Rolex used, and the cases, developed over the lifespan of the ref. 16570.

Up until 2000, the Oyster band for this model had separate hollow end-pieces that the last link in the bracelet would connect to the watch. Being lighter than current production Oyster bands, this band tended to allow a certain amount of stretch over time and can provide that customary rattle sound you find on vintage models. In 2000, they advanced to solid end links (SEL), which were integrated into the rest of the bracelet. This provided a much more solid fit of the band to the watch.

And lastly, towards the very end of the ref. 16570’s run, Rolex phased out the lug holes in the case where the bracelet attached. These models are designated ref. 16750T, with the T standing for Trous Borgnes, or Blind Holes in French.

There is no doubt the Explorer II, of any era, has lived in the shadows cast by more illustrious names in the Rolex catalog.

Yet today, they are becoming evermore popular, ironically due in the most part to their dark horse reputation. Not only are they are the plucky underdog, they are also the watches that have stuck the closest to the brand’s original ethos; hardworking, ultra reliable timepieces designed to accompany adventurers on their escapades, and tough enough to do it easily.

The ref. 16570 is certainly among the hardiest of Rolex’s creations, an honest, straightforward model with a very useful complication built in.

— Featured and Body Photo Credits: BeckerTime’s Archive.