Rolex Decades: The ‘50s Explorer Versus the ‘60s Explorer 

There is a case for calling Rolex’s Explorer the first ever tool watch. While it may not have been the first model designed to aid its wearer in some way while going about their occupation (take your pick from any number of forerunners for that distinction; Panerai’s Radiomir, Omega’s Marine or even Cartier’s Santos-Dumont, among others), the Explorer was the opening salvo in the brand’s future domination of a category they very much invented.

Tool, or sport, watches (the terms get used interchangeably most of the time, even though there are definite differences but we won’t go into that here) are now the biggest-selling genre of timepiece, and they can all trace their lineage back to one of the most understated and austere creations even the fairly conservative Rolex has ever put out.

A long-running classic, the Explorer is also one of the least altered watches from the manufacture, despite its near 70 year history.

However, as with just about everything unleashed on the world by the world’s favorite watchmaker in the ‘50s, the early life of the Explorer was relatively turbulent. Below, we take a look at how the piece was fine-tuned from its debut to the end of the 1960s.

The ‘50s Explorer Versus the ‘60s Explorer: Origins

The Explorer’s roots are about as well known as the watch itself, so we’ll just do a quick recap.

On the 29^thMay 1953, two men, Sherpa Tenzing Norgay and Edmund Hillary, finally achieved the first successful ascent of the highest peak on Earth, Mount Everest. The expedition was, in part, sponsored by Rolex and was the ninth such attempt co-funded by the brand.

As part of their contribution, the company had furnished the climbers with 20 examples of their ref. 6098 Oyster Perpetual watches; hardwearing, water resistant and automatically winding models affectionately dubbed ‘Bubblebacks’ because of their convex cases.

Upon descent, Norgay dutifully returned his watch to Rolex for study (Hillary has since revealed he wore a Smiths at the summit), and a few months later a new model, the ref. 6298 was launched.

This reference, and the ref. 6098 on which it is based, are known now as the ‘Pre-Explorers’. The ref. 6298 updated on its predecessor by including Rolex’s new three-piece case, forming an even tighter waterproof seal. In addition, the former Super Oyster Crown which was found to leak was replaced with an improved ‘Brevet +’ 6mm crown and a new tropical crystal up front gave yet more protection.

It used the same relatively rudimentary A296 caliber as before, with its bulky winding rotor still necessitating the bulging case back. And its dial, with closed minute track, arrow indexes and applied Rolex coronet was characteristically 1950s, referred to today as the ‘Everest dial’.

The ‘50s Explorer Versus the ‘60s Explorer: The Explorer Arrives

While they are Explorers in all but name, the ref. 6098 and 6298 never actually wore the title.

For that, we have to look to the follow-ups to that pair, both released in the same year, 1953. The ref. 6150 and 6350 set in place everything we look for when we think of the Explorer.

They kept the large-for-the-time 36mm steel case, but all the defining attributes were found on the dial.

The stark black on white face was given the 3/6/9 hour markers which have become the central identity of the Explorer for the last seven decades. Together with the batons and inverted triangle at the 12, the dial is legibility itself as well as having an indefinable stylistic quality which has long set the watch apart. While the earliest versions still had the pencil hands also being used on the original Submariner released around the same time, they were quickly replaced by the Mercedes type we are used to, leaving this vintage watch seeming comparatively modern.

Inside however, the power was still supplied by the same A296. In fact, the biggest difference between the ref. 6150 and 6350 was that the movement in the former was not chronometer-certified (meaning they were marked ‘Precision’ on the dial) while those in the latter were (and were marked ‘Officially Certified Chronometer’—known as OCC dials). Regardless, both had to have Bubbleback cases once again.

The ref. 6150 was in production for just one year and because it was not a chronometer and the ‘Explorer’ name didn’t appear on every example, some collectors don’t consider it the ‘first’ Explorer. That honor goes to the ref. 6350.

The ‘50s Explorer Versus the ‘60s Explorer: End of the Bubbleback

The Rolex Explorer ref. 6610
Key Features:

Production: 1955-1959
Size: 36mm
Materials: Stainless Steel
Movement: Rolex Caliber 1030
Bezel: Steel. Smooth & Fixed.
Luminescence: Radium
Dials: Black

In 1955 Rolex introduced the first movement they had devised and built entirely in-house, the Cal. 1030.

Chronometer-rated and, crucially, thinner than anything they’d used before, the time-and-date caliber was the perfect choice for the Explorer.

A new reference, the slimmed-down ref. 6610 arrived in 1956 with a far flatter case back and gave the watch the basic shape it would stick with for generations to come.

The fundamental dial furniture had also been set in stone, but here we see a few variations start to creep in during the ref. 6610’s run.

The very earliest examples have an incredibly subtle depth rating (50m=165ft) just below the Explorer name on the top half of the dial, written in either silver or red. Rolex was also experimenting with adding that to other models at the time, including the GMT-Master ref. 6542, as proof of their watches’ robust abilities.

Later on in its tenure, the ref. 6610 was given a lollipop seconds hand, with a large lume plot three-quarters of the way down to aid readability. And right at the end, a second version was released with the dot reduced in size.

But the rarest of them all has to be the ‘Albino’ model. A white-dialed Explorer, and one Rolex won’t even confirm they made in the first place, knowledgeable collectors nevertheless have verified their authenticity and now pay huge premiums for them.

Three other, much overlooked, Explorer examples were also released in the 1950s. The ref. 5500 and 5504 both shared not only a case, movement and handset but also a reference number with Air-King models of the same vintage. The only difference was the name on the dial. However, the ref. 5500 measured just 34mm while the ref. 5504 was the standard 36mm.

And the final piece, the ref. 5507, was the first and only time the Explorer would be issued with a date function. Incredibly rare, if you find one, it will have ‘Explorer Date’ printed above the spindle.

The ‘50s Explorer Versus the ‘60s Explorer: The Explorer Finds its Form…for 30 Years

The Rolex Explorer ref. 1016
Key Features:

Production: 1960-1989
Size: 36mm
Materials: Stainless Steel
Movement: Rolex Caliber 1560/1570
Bezel: Steel. Smooth & Fixed.
Luminescence: Radium/Tritium
Dials: Black

With the arrival of the ref. 1016 in 1959, Rolex clearly felt they had done enough with the Explorer for the time being. As a result, bar the occasional tweak, the reference remained pretty much unchanged until its eventual retirement in 1989.

Yet, as you can imagine, those little changes which did occur can greatly affect the value of any one piece.

The first of the ref. 1016s were powered by the Cal. 1560 and so this was the first reference to wear Rolex’s ‘Superlative Chronometer Officially Certified’ script on its dial. Later on into the ‘60s, that movement was upgraded to the Cal. 1570 which did little else but raise the balance frequency from 18,000vph to 19,800vph.

Similarly, because it hung around for so long, the ref. 1016 went through a glut of dial variations. These can be broken down in a couple of ways. First of all there are the early gilt Marks and the later matte types. The gilt can then be broken down further into the chapter ring and non-chapter ring styles. In all, collectors believe there are 12 different dials for the ref. 1016 (not including service dials), although some were from the 1970s and so fall outside our remit here.

Let’s take a closer look.

The Gilt Dials (Chapter Ring)

Mark 0—For some reason, we don’t start with a Mark I but Mark 0. This is usually because these dials were discovered later than the rest, but they can be easily identified because Rolex was still marking them ‘Officially Certified Chronometer’ despite the presence of the Cal. 1560. They weren’t around for long and exist between the 516XXX and 596XX serial range

Mark I—Appearing in the same serial range as the Mark 0 (as do all the Chapter Ring dials in fact—which is probably what has led to the confusion) the Mark I dials are the first to have the SCOC designation. One easy way to tell the four Chapter Ring dials apart is by looking at the Rolex coronet under the 12. On the Mark 0 and I, it is fairly squat with a simple base. *As an aside, this is likely the era Explorer worn by James Bond creator, Ian Fleming

Mark II—The Mark 2 gilt dial stayed in service for a good while, so their serial range goes from 516XXX all the way to 915XXX. Later examples became what are known as exclamation point dials, which have an extra dot of lume under the 6 o’clock to indicate the paint has reduced radioactivity. Of course, that doesn’t look like an exclamation point on the Explorer because of the Arabic numerals at the cardinal points, but the name was coined from versions of the Submariner and GMT-Master which have the rectangular baton indexes. Here the coronet is much more elongated and elegant looking

Mark III—The last of the Chapter Ring Marks, the Mark III lasted into the 105XXX and has an extra long coronet with large dots on the end, and is an exclamation point dial

All the Chapter Ring dials are marked ‘Swiss’ below the 6 o’clock index as they were intended to use radium for their lume.

The Gilt Dials (Non-Chapter Ring)

Mark IV—The first Explorer ref. 1016 without a chapter ring encircling the minute markers. Its removal opened the face up and gave the watch a more modern look overall. The Mark IV can be subdivided into two versions; the early models still had ‘Swiss’ below the 6, while later ones had ‘T<25’ to signify they had switched to tritium for the lume. These dials extended from the 90XXX to 105XXX serial range

Mark V—Only in use for a very short time, the Mark V can be distinguished from the spindly spikes on the coronet and the straight serifs on the E of the ‘Rolex’ logo. 10XXXXX to 115XXXX range

Mark VI—The longest running of the gilt Marks, the Mark VI went from the 1.4m to the 1.72m serial number range. Here the spikes on the coronet are more tapered and the serifs on the E slant downwards. (Yes, all these things matter!)

The Matte Dials

Mark I—The switch to matte finish dials happened around 1967 and gave the Explorer a more utilitarian look, as befit a supposed tool watch. The Mark I ran between the 1.5m and 3.5m range and is known as the Frog Foot dial, thanks to its splayed coronet. Early examples also have what are called a Fat Font, with the 3/6/9 numerals looking especially portly

Mark II—Another very short run, the Mark II matte dial has almost exactly the same font and coronet as the Mark VI gilt dial. Found on 2.1m range watches

(The Marks III to V actually take us into the 1970s and ‘80s, but I might as well include them here—because I wrote them all out before I realized, if I’m honest!)

Mark III—A difficult one to pin down, partly because its distribution was split (3.6m-4.1m and then found again on the 8m range), partly because the Mark IIIs were often used as service dials and partly because there are no real distinguishing features. Just an elegant dial, with standard coronet and nothing else

Mark IV—On the 4m to 6.6m range, the Mark IV are the easiest dials to identify due to the extremely elongated coronet

Mark V—Another dial sometimes used as a service dial, the Mark V officially exists in the 6.6m to 9m range. The sharp eyed may be able to spot the E in Rolex has its middle bar closer to the top rather than in the middle. The coronet has also shrunk a little too

The ‘50s Explorer Versus the ‘60s Explorer: Special Version

There is another ultra rare variation of the ref. 1016.

It was created exclusively for the Japanese market in 1963 to try and capture some of the country’s adulation for the astronauts of the era. A completely standard Explorer with a gilt dial, the only difference was the name had been changed to Space Dweller. Yet, even with the goodwill tour of the Mercury 7 crew bringing the country to a standstill, the Space Dweller refused to ignite in Japan and it was abandoned as a project in 1966.

The Rolex Explorer has always been an under-the-radar watch, even with its history and status as the first of its kind.

However, it is also among Rolex’s most successful designs. With literally nothing on it extraneous, it is free to do its job with no fuss or pantomime.

Like everything the brand put out in the 50s, it had an unsettled start. But once it settled into its ‘60s heyday, it was able to stick with the ref. 1016 for 30 years—and that has to be a testament to its design longevity.

Check back in with us later when we will be looking at the Explorer of the modern era.

Featured Photo: BeckerTime’s Archive.