Thanks to its 24-hour display by means of an additional hand and an engraved bezel, the Explorer II allows the wearer to clearly distinguish daytime from night-time hours. Launched in 1971, then restyled in 2011 with a case diameter of 42 mm, this watch designed for extremes is heir to the privileged relationship that has always united Rolex and exploration. In 2021, a redesign of the case and bracelet enhanced the model’s aesthetic balance and the harmony of its lines.

TO THE FAR CORNERS OF THE WORLD
Environments such as mountain tops, oceans, volcanoes and polar regions have always been experimental terrain for Rolex. Oyster Perpetual watches accompanied numerous Himalayan expeditions – including the group that Sir Edmund Hillary and Tenzing Norgay were part of when they became the first climbers to reach the summit of Everest on 29 May 1953 – and have been worn by explorers venturing to the far corners of the globe, through deserts, at the poles or in the depths of the Earth. In these often harsh and unfamiliar environments, distinguishing day from night can become impossible. For speleologists, who spend days at a time in darkness, or polar expeditions travelling under the midnight sun or through endless night, the Explorer II, with its 24-hour display, is an essential part of their equipment.

SECOND TIME ZONE
The Explorer II can also display the time in two time zones simultaneously – when the watch’s additional hand, along with the graduated bezel, is not being used to indicate the time in 24-hour format, a second time zone (reference time) can be read. Local time is shown by the conventional hour hand and can be set easily, with the hour hand ‘jumping’ from hour to hour thanks to a mechanism operated via the winding crown. The adjustment can be made independently of the minute and seconds hands, and without affecting the 24-hour hand (showing the reference time). As a result, the wearer can simultaneously read the local time and a reference time.

CHROMALIGHT DISPLAY
The Explorer II is an extremely legible watch in all circumstances. The simple high-contrast dial is easy to read, even in the dark, thanks to the Chromalight display: the hour markers and hands are filled or coated with a luminescent material emitting a long-lasting blue glow.

THE OYSTER CASE, SYMBOL OF WATERPROOFNESS
The Explorer II’s Oyster case, 42 mm in diameter and guaranteed waterproof to a depth of 100 metres (330 feet), is a paragon of robustness and reliability. The middle case is crafted from a solid block of Oystersteel. The case back, edged with fine fluting, is hermetically screwed down with a special tool employed by approved watchmakers. The Twinlock winding crown, fitted with a double waterproofness system and protected by an integral crown guard, screws down securely against the case. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire and benefits from an anti-reflective coating. The waterproof Oyster case provides optimal protection for the movement it houses.

BRACELET AND CLASP: SECURITY AND COMFORT
The Explorer II is available on a three-piece link Oyster bracelet. This bracelet is equipped with a Rolex-designed Oysterlock safety clasp, which prevents accidental opening. It is fitted with the Easylink comfort extension link, developed by the brand, which allows the wearer to easily increase the bracelet length by approximately 5 mm, for additional comfort in any circumstance.

CALIBRE 3285
The Explorer II is equipped with calibre 3285, a self-winding mechanical movement entirely developed and manufactured by Rolex. A distillation of technology, this movement carries a number of patents. It offers outstanding performance, particularly in terms of precision, power reserve, convenience and reliability.

Calibre 3285 incorporates the patented Chronergy escapement, made of nickel-phosphorus, which combines high energy efficiency with great dependability and is resistant to strong magnetic fields.

The movement is additionally fitted with the blue Parachrom hairspring. Manufactured in a paramagnetic alloy enabling it to withstand strong magnetic fields, this hairspring also offers great stability in the face of temperature variations as well as high resistance to shocks. It is equipped with a Rolex overcoil, ensuring the calibre’s regularity in any position.

The oscillator of calibre 3285 has a large balance wheel with variable inertia regulated extremely precisely via gold Microstella nuts. It is held firmly in place by a height-adjustable traversing bridge enabling very stable positioning to increase shock resistance. The oscillator is also mounted on the Rolex-designed, high-performance Paraflex shock absorbers, further enhancing the movement’s shock resistance.

Calibre 3285 is equipped with a self-winding system via a Perpetual rotor, which ensures continuous winding of the mainspring by harnessing the movements of the wrist to provide a constant source of energy. Thanks to its barrel architecture and the escapement’s superior efficiency, the power reserve of this movement extends to approximately 70 hours.

The Explorer II’s movement is beautifully finished and decorated. Since 2023, it has also been marked with the words ‘Chronometer Perpetual’ and ‘Superlative Adjusted’ engraved on the oscillating weight and on the bridges, respectively.

THE EXPLORER II, SUPERLATIVE CHRONOMETER CERTIFIED
Like all Rolex watches, the Explorer II is covered by the Superlative Chronometer certification. Symbolized by a green seal, this in-house certification is strictly controlled by internationally recognized, independent Swiss entities. It ensures the excellent on-the-wrist performance of each of the brand’s watches and is coupled with an international five-year guarantee.

In 2026, the Superlative Chronometer certification was expanded to seven testing criteria. Resistance to magnetism, reliability and durability were added to the criteria for precision, waterproofness, self-winding and autonomy, established when the certification was redefined in 2015.

The requirements in terms of precision are particularly stringent. Each Rolex movement is first officially certified as a chronometer. This means that, having passed a series of eliminating tests, it fulfils the criteria governing the ‘chronometer’ designation for wristwatches. For the category of calibres concerned, which includes all Rolex movements, the tolerated rate deviation is –4 and +6 seconds per day.

After casing the movement, the precision is then tested again, following a protocol developed by Rolex that simulates real-life wearing conditions, to meet even stricter criteria: the watch’s accuracy must be between –2 and +2 seconds per day. The rate deviation tolerated by the brand for a finished watch is therefore significantly smaller than that accepted for official certification of the movement alone.