Rolex Explorer II Ultimate Guide

Rolex Explorer II Models Ultimate Guide

The Rolex Explorer II has come to embody the all-around sports watch, but it is in fact one of the most niched watches that Rolex has ever produced. Launched in 1971, its design was especially geared towards spelunkers and cave explorers who spend long periods away from natural light. The Explorer II’s 24-hour bezel and large hour markers were meant to help them distinguish the hours from day to night.

Today, the Rolex Explorer II is not only used in far off mountaintops, it’s also well-suited for a wide variety of settings – from daily office wear and weekend excursions, to daytime events and even nights out.

Not that long ago, the Rolex Explorer II received less attention from one of its famous siblings like the Submariner or GMT-Master II, but with its versatile design, it’s now up there with the rest of Rolex’s stainless steel sports watches in terms of demand.

Looking to own a Rolex Explorer II? Learn more about this trusty adventure and everyday piece with SwissWatchExpo’s Ultimate Guide.

Two generations of the Rolex Explorer II: reference 216570 and 1655

A Brief History of the Rolex Explorer II

Introduced in 1971, the Rolex Explorer II was created as an addition to the existing Explorer collection.

While the original Explorer (or Explorer I) entered the market in 1953 as a rugged time-only watch for use in a variety of demanding activities, the Explorer II was specifically designed for speleologists and spelunkers. The additional 24-hour bezel and bright 24-hour hand on its dial was meant to help the wearer keep track of daytime and nighttime hours as they spend extended periods of time in low-light situations and even complete darkness.

Rolex Explorer I and Rolex Explorer II models.

As is the case with long-running models in Rolex’s catalog, the Explorer II has undergone several iterations throughout its history, while staying true to the collection’s original design and purpose.

Here are important milestones in the history of the Rolex Explorer II:

1971 – The first Rolex Explorer II is introduced with the reference 1655. It is a stainless steel watch just like the original Explorer, but it comes with the addition of a 24-hour bezel and bright orange 24-hour hand. This meant that from a time-only watch, the Explorer II is a dual time watch.

1985 – The Rolex Explorer II is launched with a more modern appearance. The reference 16550 introduced contemporary features such as a 40mm case, a wider bezel with larger numbers, and luminous dot hour markers, which we still see in today’s Explorer II.

1989 – After four years, the reference 16550 was replaced with the 16570. Both models are very similar in design; the major change was the upgrade to the Caliber 3185 and later the Caliber 3186. It also marked the change of luminous material from Tritium, then Luminova, and eventually SuperLuminova.

2011 – The six-digit Rolex Explorer II reference hit the market in time for the Explorer II’s 40th anniversary. To honor the original ref 1655 model, Rolex brought back the bright orange 24-hour arrow hand.

2021 – Rolex released a brand new generation of the Explorer II to celebrate its half-century. This model is incredibly similar to the previous reference but its case and lugs are slimmer, and its bracelet slightly wider, resulting in a more refined silhouette. It was also equipped with an updated movement, the Caliber 3285.

Key Characteristics of the Rolex Explorer II Collection

The Rolex Explorer II is one of the brand’s most tool-oriented models, with a design made specially to aid cave exploration. Here are the distinguishing features of the Rolex Explorer II.


Case diameter:39mm (1971- 1985); 40mm (1985 – 2011); 42mm (2011-)
Material:Stainless steel / 904L Steel / Oystersteel
Functions:Time and date; dual time (1971-1985) or GMT (1985 -)
Bezel:Fixed 24-hour bezel
Dial:Black or white with round, baton and triangular markers
Water resistance:100m 

Oyster Case

All versions of the Rolex Explorer II have an Oyster case and it has been made exclusively in stainless steel since 1971. The Oyster case was created by Rolex back in 1926, and it gets its name from the hermetic seal it provides. This is achieved through patented system of securing the bezel, case back, and crown against the case, resulting in maximum water resistance and protection from dust and moisture.

It also provides the Explorer II its 100m (330 feet) water resistance rating, which will come in handy if the wearer is exposed to water or moisture during sports and outdoor activities. Rolex has made the Explorer II using 904L steel since 1985, which has superior corrosion resistance compared to the standard 316L steel used by many watchmakers.

Rolex Explorer II models have Oyster cases in stainless steel

Oyster Bracelet

The Explorer II’s case has a matching stainless steel Oyster bracelet. The Oyster bracelet is characterized by three-piece links with a wide center, and a brushed finish all over. It is considered the sportiest in design among Rolex’s bracelets.

In modern Explorer II models, the bracelet comes with an Oysterlock clasp that locks the bracelet into place and prevents accidental opening. In 1996, the patented Easylink Extension System was added to the Explorer II – it allows for the bracelet to be adjusted in 5mm increments even without the use of tools. This feature is especially useful during hot seasons as it allows the wrist to breathe.

24-Hour Bezel

This feature is a pillar of the Explorer II and was specifically added to help with its purpose. The 24-hour gradations on the bezel can either help track daytime and nighttime hours, or display a second time zone, depending on the Explorer II model. These numbers correspond to the additional arrow hand that circles the dial once every 24 hours.

The Rolex Explorer II bezel has always been fixed or stationary. It does not rotate like the Submariner or GMT-Master’s bezel.

After the reference 1655, Rolex Explorer II models already have a choice between a black and white dial


Various dial changes have taken place in the Explorer II’s history, but what has remained consistent are the luminous baton numerals at 6 and 9 o’clock, a triangular marker at 12 o’clock, and the date window at 3 o’clock which is magnified by a Cyclops lens over the crystal.


The Rolex Explorer II has always been powered by automatic, self-winding movements. They are all equipped with the perpetual rotor, which relies on the movement of the wearer’s wrist in order to stay wound.

Below are the movements that have been used for the Explorer II line:

1575 – found inside the ref 1655. This was the same movement used in the GMT-Master at the time, which features hacking seconds that stops the seconds hand from moving while setting the time.

3085 – found inside the ref 16550. This was the first movement that Rolex produced in-house that featured independently adjustable hour hands, thus turning the Explorer II from an AM/PM indicating watch, to a GMT watch.

3185 – found in the ref 16570. This movement replaced the short-lived 3085, but is similar in design and functionality. Improvements made include greater shock resistance and a slimmer profile.

The current edition of the Rolex Explorer II is powered by the Caliber 3285


3186 – found in the ref 16570. This movement corrected the slight wobble found on the 3185 when using the jump-hour feature, thanks to Rolex’s famous blue Parachrom hairspring.

3187 – found in the ref 216570. As the new model increased in size from 40mm to 42mm, this movement was also enlarged to fit the case. It also comes with Rolex’s Paraflex shock absorbers for improved protection against impact.

3285 – found in the ref 226570. This new generation movement is also found in the GMT-Master II line. It features the brand’s proprietary Chronergy escapement which improves efficiency by 15%, and offers a power reserve of 70 hours.

Generations of the Rolex Explorer II

The Rolex Explorer II has gone through various changes in terms of appearance and technical features. Let’s take a look at the evolution of its models.

ROLEX EXPLORER II ref 1655 (1971 – 1984)

Case size: 39mm
Movement: Caliber 1575
Luminous material: Tritium
Crystal: Acryclic

The first Rolex Explorer II was introduced in 1971 as an additional range within the Explorer collection. Its first reference was the 1655.

This model featured a 39mm stainless steel case and a smooth, fixed bezel with 24-hour markings. What sets its bezel apart from the rest of Rolex sports watches is that it is fixed and non-rotating. Moreover, the Explorer II had its graduations engraved onto the bezel itself, without using aluminum inserts.

Rolex Explorer II ref 1655 also known as the “Freccione”

The first Rolex Explorer II was introduced in 1971 with the ref 1655. It featured a 39mm stainless steel case, and a fixed 24-hour bezel. Unlike the Submariner and the GMT-Master, its bezel is non-rotating and its markers engraved directly on the bezel, without the use of inserts.

Its other unique feature was the bright orange 24-hour arrow hand. This arrow was intended to hold more tritium lume hence its size, which would make it easily readable even in pitch dark caves. For the reference 1655, the 24-hour hand was not yet an independent hand, which meant one had to move both the hour and minute hands to adjust it as well. Moreover, this meant that the ref 1655 is a dual time or AM-PM indicator, and not yet a GMT.

Rolex also experimented with various types of fonts and logos for the dial of the ref 1655, resulting in five different versions which collectors refer to as Mark I through Mark V.

This model has earned the moniker “Freccione” or “big arrow” in Italian because of its striking bright orange hand. It was also rumored that the racer-actor Steve McQueen wore this particular reference, so many collectors refer to it by his name – however, no evidence has surfaced that he ever wore or owned one.

ROLEX EXPLORER II ref 16550 (1985 – 1989)

Case size: 40mm
Movement: Caliber 3085
Luminous material: Tritium
Crystal: Sapphire

The Rolex Explorer II design that we see today began to take shape with the introduction of the ref 16550 in 1985. One can already see the makings of a modern Rolex sports watch with its 40mm stainless steel case, wide bezel, and alternating Arabic numerals and inverted triangles. The hash marks previously seen on the 1655 were replaced by luminous hour markers that take the form of dots, batons, and a triangle. The stick hands were replaced by the Mercedes-style design, and the bright orange hand was replaced by a sleeker red one with a slightly smaller arrowhead.

Rolex Explorer II ref 16550

One interesting fact about this model is that Rolex experimented with white paint for its markers. This type of paint later on resulted in oxidation and gave the markers an ivory white shade. While this might be considered a defect, models with these markers are highly sought-after for their unique appearance, and are some of the most expensive examples of the ref 16550.

It was also with the ref 16550 that the sapphire crystal was introduced (from an acrylic crystal) and the Explorer II was given the option of a white dial (from just black). Finally, this model was also equipped with the Caliber 3085 movement. This new caliber allowed for an independently adjustable 24-hour hand, which also meant that the Explorer is no longer just an AM/PM watch, but a GMT watch with a jumping hour hand.

This reference ran for four short years until it was replaced in 1989.

ROLEX EXPLORER II ref 16570 (1989 – 2011)

Case size: 40mm
Movement: Caliber 3185 / 3186
Luminous material: Tritium, Luminova, SuperLuminova
Crystal: Sapphire

The reference 16570 took the place of the 16550 in 1989. These two models look very similar and the changes made were on the technical side. First, the movement was upgraded from the Caliber 3085 to the 3185 (and later the 3186). These new movements featured Rolex’s patented Parachrom hairspring which solved a slight tick on the 24-hour hand, which wearers pointed out when using the jumping hour feature.

On the dial, Rolex replaced the white gold surrounds of the hour markers with ones that were finished black, complementing the hands and resulting in a more legible read. Over its production period, Rolex also used different types of lume – beginning with Tritium, then Luminova, and finally, SuperLuminova.

Along the way, the ref 16570 also received an upgraded rehaut engraved with the Rolex name and the watch’s serial number, an additional safeguard against counterfeiting.

This reference is currently the longest-running one from the Explorer II collection.

ROLEX EXPLORER II ref 216570 (2011 – 2021)

Case size: 42mm
Movement: Caliber 3185 / 3186
Luminous material: Tritium, Luminova, SuperLuminova
Crystal: Sapphire

In time for the 40th anniversary of the Rolex Explorer II, they introduced the six-digit reference 216570. As a homage to the inaugural reference 1655, Rolex changed the red arrow hand to an oversized bright orange arrow hand.

Rolex Explorer II ref 216570

The case size was also increased to 42mm from 40mm. With more space to occupy, this made many of the watch’s elements larger: the crown and crown guards, the numbers on the bezel, the luminous hour markers on the dial, the hands, and even the index markers.

The luminescence used on the hour markers was also updated to Chromalight (from SuperLuminova). It promises a longer-lasting 8-hour glow, and is characterized by its blue light.

Lastly, Rolex also upgraded this reference with the Caliber 3187, which has Rolex’s own Paraflex shock absorbers, which protect the movement from impact.

ROLEX EXPLORER II ref 226570 (2021 – present)

Case size: 42mm
Movement: Caliber 3285
Luminous material: Chromalight
Crystal: Sapphire

For the Explorer II’s 50th anniversary in 2021, Rolex gave the watch subtle updates. While Rolex fans were expecting a major change – such as a Ceramic bezel – Rolex only refined the previous ref 216570 and upgraded its technical features.

Rolex Explorer II ref 216570 and 226570

The case remained at 42mm and its proportions were refined. They were updated with thinner lugs, while the slightly wider bracelet gave it a more balanced look. The crystal was also given anti-reflective coating for better reading under natural light, and they also optimized the Chromalight display to improve its legibility.

The current Rolex Explorer II is powered by the new generation Caliber 3285 movement, which features the Chronergy escapement and boasts of longer, 70 hours of power reserve. 


165539mm1971 – 1984Stainless SteelCal. 1575
16550 / 1655540mm1985 – 1989Stainless SteelCal. 3085
1657040mm1989 – 2011904L SteelCal. 3185 / 3186
21657042mm2011 – 2021OystersteelCal. 3187
22657042mm2021 – presentOystersteelCal. 3285


Common Questions About the Rolex Explorer II

Is the Rolex Explorer II a good investment?

The Rolex Explorer II may have had various changes in its lifetime, but they are among the most conservative in Rolex’s history. This is proof of the timelessness of the design.

In particular, there is very little difference in the aesthetics of the latest two models – the ref 216570 and 226570. Aside from upgrading the movement, Rolex only tweaked the case and bracelet design to make it more elegant.

Rolex Explorer II ref 216570 and 226570

Due to this lack of major difference between these two models, the ref 216570 makes for a good option if you want a modern Rolex Explorer II, but at a more affordable price. While Rolex has ceased production for this model, it is available in the pre-owned market.

Furthermore, the demand for the Rolex Explorer II has increased in previous years due to the continuing popularity of stainless steel sports watches. Demand for stainless steel sports watches is expected to rise in the coming years, making the Rolex Explorer II a wise investment.

Is the Rolex Explorer II a GMT watch?

It depends on the model. The ref 1655 is a time-and-date watch with an AM/PM indicator on the bezel.

Beginning with the reference 16550 and the Caliber 3085, the Rolex Explorer II has been equipped with an independently adjustable hour hand and can display more than one time zone simultaneously. With this development, the Rolex Explorer II evolved from an AM/PM watch to a GMT watch.

Rolex Explorer II ref 16550

Here’s how it works: you can configure the watch so that the standard, Mercedes-style hour hand indicates local time or time in your current location, while the red or orange arrow hand points to the 24-hour bezel and displays the reference time (this could be GMT, your home time, or any other time zone that you choose). The date window at 3 o’clock can also be configured to show the date in the current local time zone.

How will I know if my Rolex Explorer is genuine?

Rolex watches are built to meet the highest quality standards. If you see any sign of a design flaw on the watch such as a misaligned marker or misspelled text, unfinished or crooked surfaces, or wrong engravings and markings, then the watch is most likely a counterfeit.

We always recommend doing research on your desired watch model to help you become familiar with its correct features, such as the type of hands, designs of the markers, and the text above 6 o’clock. The smallest details like these will help you in checking if the watch is indeed genuine.

While it’s always advisable to check for authenticity yourself, the best way to avoid counterfeit watches is to purchase a watch from a reputable and trusted dealer, such as SwissWatchExpo, who is able to provide a guarantee of authenticity on the watch.

Rolex Explorer II ref 1655

Is the Rolex Explorer waterproof?

Rolex Explorer II models, both vintage and modern, are water resistant to a depth of 100 meters (330 feet), thanks to their Oyster case. It was not made specifically for diving, but they come with screw-down crowns and case backs, which protect the movement from moisture that can be encountered with daily use.

Has the Rolex Explorer II been discontinued?

The Rolex Explorer II remains in the Rolex catalog as of 2022, and was in fact updated in 2021 in time for its 50th anniversary. Previous models of the Explorer II, from the inaugural ref 1655 until the modern ref 216570 are available in the pre-owned market.



Rolex Explorer II – Final Thoughts

From being Rolex’s most niched tool watch, the Rolex Explorer II has become the no-frills sports watch that can be used for just about any occasion.

Because of its half-century history, you have many options when buying a Rolex Explorer II. You can go for the ref 1655 if you want a vintage version with patina, character, not to mention an illustrious history.

If you want the reliability of a modern watch but want a more modest size, the Explorer II models with 40mm cases would suit you best. For a sleek, contemporary watch with unparalleled accuracy and legibility, you have the six-digit references to choose from. The Rolex Explorer II makes for a reliable companion, whether you’re using it every day or when the peaks call you.

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