The History and Development of Rolex Explorer II

Ever since Rolex made their first waterproof watch in 1927, they have been making watches for specific groups of professionals and sports people. From the Rolex Submariner, made to be used by professional divers, to the GMT Master II made for transatlantic airline pilots, to the Rolex Daytona for race-car drivers, it's safe to say that Rolex caters for very specific needs to sell watches to the masses. One of the more unknown professions that Rolex caters to however is with their Explorer range. Now it's pretty obvious that their watches are made to be used by, well, explorers. Whilst this is true, many people just think of the 1953 Everest climb by Sir Edmund Hillary and Tenzing Norgay, where Norgay famously wore a Rolex Oyster Perpetual on his wrist that would eventually be branded the Explorer. But almost 20 years after that, Rolex released another watch to complement the Explorer, the Rolex Explorer II. Whereas the Rolex Explorer was created for people climbing to the top of some of the highest peaks on earth, the Explorer II was created for people going under them, cavers. As is obvious, a caver (or spelunker) is someone who explores caves, thus presenting a whole different set of criteria for Rolex to cater for when compared with the standard Explorer.

The first Rolex Explorer II, released in 1971, was given the reference number 1655. The Explorer II ref 1655 had a steel case, with a steel oyster bracelet and a black dial, but that is where the similarities between the Explorer, and its new sibling end. As it was made to be used underground for long periods of time, the Explorer II ref 1655 had some unique features to make it practical in its intended setting. The case measured in at 39mm. Which helped with legibility, as it was much bigger than was normal for its day.

The large steel case was paired with relatively thick white hour, minute and second hands to contrast the black dial, as well as a striking orange 24 hour hand, that pointed to a steel bezel on the outer edge of the case, numbered with the even numbers from 1 to 24. This is not to be confused with the 24 hour hand on the Rolex GMT master (although they used the same calibre 1575 movement at the time) as with its rotating bezel the GMT Master uses the function to tell dual time zones, and on the Explorer II with its fixed bezel it is used to tell the wearer if it is AM or PM, something that is not always obvious when working underground with no sunlight. On later models of the Explorer II, it is possible to use it to tell dual time zones.

As can be expected for a watch made to be used in low light, the dial and hands had a generous application of lume, with the now iconic triangle tipped, orange 24 hour hand having a large triangle of luminescent material in it, the hour and minute hand also had plenty of lume, and the dial had large luminescent markers at 5 minute intervals, with smaller ones inbetween. This made sure the user of the Rolex Explorer II 1655, had the best chance of reliably being able to tell the time, overground or underground, in daylight or darkness.

The current Rolex Explorer II (ref 216570) has been in production since 2011, although since its birth in 1971 there have been a total of 5 Explorer II models. The first, ref 1655, had a 13 year life span before being replaced with the ref 16550 in 1985. The 16550 saw multiple changes to the design and function of the watch, including a larger, redesigned 40mm case, with sapphire crystal glass. It also featured the now instantly recognisable ‘Mercedes’ hands, along with a redesigned smaller 24 hour hand that was red instead of orange, as on the 1655 it replaced. Ironically, almost all of the red 24 hour hands on the ref 16550 have now faded to look orange anyway. The 16550 was also made available with an option of a white dial, sometimes referred to as the ‘polar dial’. Often the paint used on the older white dials can fade to a cream colour and is now very desirable among collectors. The ref 16550 is also where we see a change to dial design, introducing the round applied hour markers, similar to the ones seen on the Submariner and GMT master range.

As well as cosmetic changes, the 16550 was also given the newer calibre 3085 movement. This movement was also used in the GMT master II, meaning the hour hand was now independently adjustable, making it possible to show a second time zone.

The 16550 is often referred to as a transitional model. This is because in 1989 it became the ref 16570, essentially the same watch as the 16550, but with a Rolex calibre 3185, it is considered the first ‘modern’ Explorer II. This modern Explorer II ref 16570 ran for over two decades before being redesigned in 2011, to become the latest ref 216570.

 Over the years, Rolex have become very good at updating their models in a way that allows the design of a watch to remain recognisable when compared to past reiterations, whilst feeling as fresh and modern as a new watch should. This is no more evident than in the current Rolex Explorer II ref 216570. Its DNA is instantly recognisable as being derived from its 1970s ancestor, the original ref 1655. The watch sports its classic fixed steel bezel with 24 hour markings, matched with the orange broad arrow 24 hour hand reminiscent of the original ref 1655. It now also has a further increased case diameter of 42mm, along with a modern steel oyster bracelet with the Oysterlock clasp and 5mm extension.

2021 is a very exciting year for the Rolex Explorer II, as it celebrates its 50th anniversary. Traditionally, Rolex makes a special addition to commemorate the 50th anniversary of one of its models. They are normally received well, showcase the latest technology, and influence the models future designs (think Submariner Kermit, or Ceramic GMT Master). Towards the end of 2020 and the beginning of 2021 the rumour mill is definitely running on full power, with speculation and predictions from some suggesting everything from the introduction of a ceramic bezel to the range, to going back to a smaller case size, to more dial colours, to a steel and 18ct yellow gold option. One thing is for sure, anticipation is high, and very soon the often overlooked Rolex Explorer II ref 216570 will become more desirable as a new model replaces it.

Author: C Lawson