The Explorer, launched in 1953, set itself apart with a simple design and a highly legible black dial with large hour markers and characteristic 3,6,9 numerals. It is a tool watch, created to tell time accurately, whatever the circumstances.

Long after the light dies, you can tell the time. The Explorer’s Chromalight hour markers and hands contain luminescent material that emits a lasting blue glow ensuring excellent legibility even in the dark.

In 1971, the Explorer II is introduced and, in the same spirit as the Explorer, it perpetuates the privileged relationship that Rolex enjoys with exploration.

The Explorer II features a date display, an additional orange 24-hour hand and a fixed bezel with 24-hour graduations, enabling day to be distinguished from night. It became the watch of choice for speleologists, volcanologists and polar explorers.

The additional arrow-shaped 24-hour hand of the Explorer II circles the dial once a day and is used in relation to the engraved fixed bezel. It can indicate the time in a second time zone or show the time in 24-hour format – a practical option in places where distinguishing day from night is impossible, such as at the poles or in caves.

The Explorer and Explorer II are made of Oystersteel. Specially developed by Rolex, Oystersteel belongs to the 904L steel family – superalloys that are most commonly used in high technology such as in the aerospace and chemical industries. Oystersteel is extremely resistant, offers an exceptional finish once polished and maintains its sheen even in the harshest environments.

The Twinlock winding crown on the Explorer and Explorer II is fitted with a double waterproofness system. It features two sealed zones, one inside the tube, the other inside the crown. This principle is used on most of the watches in the Oyster collection that are guaranteed waterproof to 100 metres (330 feet).

The Explorer is equipped with calibre 3132 and the Explorer II with calibre 3187, both self-winding mechanical movements entirely developed and manufactured by Rolex. They feature a Parachrom hairspring that provides great stability in the face of temperature variations, and Paraflex shock absorbers offering greater resistance to shocks.

From the 1930s, Rolex began to equip numerous expeditions with Oyster watches. The feedback received over the years was used to develop what became known as the Professional category of watches that served as tools: models such as the Explorer and Explorer II.

The information gained from the Everest expedition, as well as feedback provided by other climbers, led the brand to launch the Explorer watch. Later, the performance of the Explorer model was enhanced with a reinforced case and a more legible dial, catering to extreme conditions.

Over the years, many explorers, mountaineers and scientists became Rolex Testimonees and were breaking records and testing their endurance and courage in creative ways, often equipped with Explorer and Explorer II watches.