The Rolex Explorer II
In 1971, Rolex came out with a new adventurer’s watch aptly named the Explorer II, designed especially for cave explorers. This model was a true achievement because it had a feature that could help the speleologists (cave explorers) to know whether it was day or night. Finally, cave explorers spending multiple days at a time in deep caverns, would be able to keep proper track of the time.
The Rolex Explorer II was given the model number 1655 when introduced in 1971. It featured crown guards, a new fixed and engraved 24 hour bezel, and an extra orange colored 24-hour hand. This extra 24-hour hand, when used against the bezel, helped to distinguish day from night by clearly differentiating AM from PM. The 24-hour engraved bezel in this model makes it, essentially, a GMT Master. In addition, it has the same caliber movement as the GMT (1575). It also features a 12-hour hand that can be adjusted to allow changes in time zones.
Major Changes Over Time
The first improvement came in the form of a red-colored extra 24-hour hand as opposed to the orange color in previous versions. In the pitch-black darkness of the deep caves, red was easier on the eyes than orange. By mid 1985, the new Explorer II was launched with the following new features included:
- Standard 40mm case size
- New bezel rendering the Explorer II a stylish look
- Mercedes hands in place of old, large stick hands
- A slimmer sapphire crystal
- Black and white dial options
- Special 24-hour hand and same "jump hour" feature as that of the GMT Master II
The jump hour feature in the new Explorer II allows the owner to set the hour hand forward or backwards in one hour jumps without disturbing the second or minute hands. In other words, the owner can easily change time zones without losing a preset accurate time.
Today, of the several different Explorer II models offered by Rolex, the model available in steel with a white dial is the most popular. Like other Rolex models, it is self-winding and waterproof to 330 feet. It also features an Oysterlock bracelet with a safety clasp. Even for explorers in harsh conditions in the depths of caves, Rolex offers the unique combination of class and precision.