Rolex’s Explorer II reference 16550 replaced the beloved reference 1655, which was a modernized version of the brand’s historic Explorer line of wristwatches. The unique design was originally intended for spelunkers (cave explorers), with a fixed, engraved 24-hour calibrated bezel and an additional 24-hour hand that permits the wearer to easily know the correct time in the darkness of caves. The 24-hour hand indicates the time on the non-rotating 24-hour calibrated steel bezel. While reminiscent of the 24-hour rotating bezel of the GMT-Master, this watch is not for dual time purposes, but solely for those who are in darkness for prolonged periods of time to enable the wearer to differentiate night and day.

The reference 16550 was a milestone reference. It was introduced in 1985 and was the first Rolex model fitted with a scratch-resistant sapphire crystal. Produced for only a few years, white dial examples have become a collector’s favourite due to a manufacturing flaw, with the original white colour turning very pleasing ivory or cream hue over time. Earliest version so the reference provides further intrigue with their attractive “rail” dial configuration found in the perfect alignment of the vertical space between the written text across the two lines of text on the dial at 6 o’clock with “Superlative” and “Officially” words on the left, and “Chronometer” and “Certified” words on the right.

The present lot is special in its own rights, the dial has not developed any change of colours over the years which was commonly seen with other similar examples found in a similar case ranges. The white gold applied luminous hour markers that have aged to orange hues further compliment the dial of the present example.