Rumor has it that Rolex initially designed the Explorer for cave exploration. Explorers would often use the GMT functionality, not for its intended use of the second time zone feature, but as an AM/PM indicator. Due to the lack of natural light, underground explorers could spend days underground, and differentiating between day and night was particularly useful. To utilize this functionality users had to synchronize the 24-hour GMT hand with the 12-hour time. This is possible due to its independently adjustable hands, which are remarkably difficult and expensive manufacturer functionality.
The fourth generation of the Explorer is the Explorer II 216570. Recognized for its “polar” dial, 24-hour fixed outer bezel, enlarged hands and hour markers, and an iconic bright orange 24-hour arrow hand. The modern yet emboldened timepiece is a 42 mm satin finish on a stainless-steel oyster bracelet. 2021 was the last year of production for the 216570 model, rendering it discontinued.
A noteworthy detail is nearly all Explorer “polar” dials regardless of reference are worth more than their classic black counterparts. An uncommon watch in comparison to a Daytona or submariner due to much fewer in production. Throughout the history of the Explorer, it’s been one of the most underrated and overlooked models in Rolex’s entire catalog. However, more recently its popularity has risen due to the lack of availability in AD retail of the Submariner, Daytona and GMT-Master II. Due to its discontinuation, this model is more collectible than ever.