Rolex Explorer II 16570 40MM Black Box & Papers

Rolex Explorer II 16570 Black Dial (1999)

A Compact Summary of the Explorer II Lineage

Rolex released the first Explorer II (ref. 1655) in 1971 for speleologists needing a 24-hour display underground. The reference evolved through the short-lived 16550 before settling into the third-generation 16570, produced from 1989 to 2011, the longest run for any Explorer II variant. Its extended lifespan meant many subtle component updates, creating clear year-by-year fingerprints—ideal for anyone wanting to pin down a specific production period.  

1999: The Transitional Moment

The featured watch sits in the A-serial batch delivered in 1999, a sweet-spot year where Rolex had just switched from tritium to Luminova but had not yet added “Swiss Made” under six o’clock. Instead, the dial carries the minimalist “SWISS” signature, unique to a roughly twelve-month window. This detail, teamed with a fixed 24-hour bezel and vivid red GMT hand, means the 1999 model captures a highly specific slice of the Explorer II timeline.  

Case and Bezel Architecture

Like all 16570s, the 1999 edition uses a 40 mm 904L stainless-steel Oyster case rated to 100 metres. It retains drilled lug holes, making strap changes straightforward, and it shares the brushed, fixed 24-hour bezel introduced on the 16550. The bezel numerals are engraved then infilled with durable black enamel, ensuring legibility even after decades of wear. The case profile balances thin mid-case flanks with wide, flat lugs—classic late-1990s Rolex proportions that slide neatly under a jacket cuff.  

Dial Layout and the “SWISS” Signature

The gloss-black dial uses applied white-gold hour markers topped with Luminova. In low light the markers glow green, a clear departure from the cream-toned tritium on 1998 and earlier pieces. The pared-back “SWISS” text at six o’clock is the giveaway that marks 1999 production. Coupled with Mercedes hour and minute hands, a lollipop-style seconds hand and the red 24-hour hand, the layout provides instant at-a-glance reading of two separate time zones. A Cyclops magnifier over the date maintains brand continuity while adding real-world practicality.  

Calibre 3185: Engineering Inside

Power comes from Rolex’s in-house calibre 3185. Beating at 28,800 vph, the movement includes a jumping-hour mechanism that lets the local-time hour hand move independently in one-hour increments without stopping the balance. That means a quick time-zone adjustment without losing precision. The 3185 uses a traditional balance bridge, a Breguet overcoil and a free-sprung Microstella regulator. With a 50-hour power reserve and a full balance guard system, it balances robustness with accuracy that regularly meets or exceeds chronometer standards.  

Bracelet and Wearing Experience

Most 1999 examples left the factory on the Oyster reference 78790 bracelet with hollow end links and a flip-lock clasp. Solid end links (SEL) would follow in 2000. The bracelet’s taper from 20 mm at the lugs to 16 mm at the clasp delivers a comfortable, balanced feel on the wrist, while the brushed finishing mirrors the sport-tool identity of the watch. The overall weight is lighter than later SEL versions, something many enthusiasts cite as adding to the model’s wrist comfort.  

Lume Transition: From Tritium to Luminova

Rolex made the leap from tritium to Luminova in 1998. Watches built that year kept the older “T < 25” dial text even though they used the new lume, while 1999 models adopted the single-word “SWISS.” By 2000 Rolex printed “SWISS MADE” on the dial, still using Luminova until the rapid upgrade to Super-Luminova later that year. This staggered rollout means 1999 pieces act as a clear transitional marker within the reference.  

Practical Utility, Not Theatrics

Apart from the obvious dual-time function, the fixed bezel and red GMT hand make 16570 operation intuitive: set the red hand to a home-time 24-hour scale, jump the main hour hand when travelling, and use the bezel markings to track night or day. The absence of a rotating bezel simplifies the profile and removes the risk of accidental bumps altering a second-time-zone reading. The slim case and low crystal further support everyday wear.

Wearing the 1999 Black-Dial Explorer II Today

On the wrist, the 40 mm case feels balanced because the bezel diameter matches the case, avoiding the illusion of bulk. The black dial with white text creates a crisp, high-contrast appearance, while the red GMT hand adds a controlled flash of colour. It sits comfortably under sleeves yet presents enough visual interest to stand alone with short-sleeved summer attire.

Legacy Within the Explorer Family

The 16570 refined rather than reinvented the Explorer II concept. By using the thinner case of the GMT-Master II of the same era, Rolex positioned the watch as a more travel-friendly tool while retaining the 24-hour bezel crucial to its spelunking roots. In 2011 the line grew to 42 mm in the 216570, but many still view the 40 mm 16570 as the sweet-spot in terms of design purity and versatility.  

Why 1999 Matters in the Reference Story

Because 1999 straddles lume, dial-print and bracelet-spec changes, a black-dial Explorer II from that year neatly encapsulates Rolex’s incremental improvement philosophy. It offers modern-enough Luminova for night-time use, yet preserves classic lug holes and non-SEL bracelet architecture. Those details combine to deliver a watch that feels authentically late-1990s without straying into earlier tritium ageing issues or later mixed-movement uncertainties.  

Final Thoughts

A 1999 Rolex Explorer II 16570 in black captures a transition phase where Rolex modernised materials yet maintained vintage hallmarks. Its “SWISS”-only dial, calibre 3185 heart and hollow-end-link bracelet anchor it firmly in a single production year, giving owners a tangible link to a moment when the brand balanced heritage with subtle innovation. The result is a straightforward dual-time companion that still mirrors the pragmatic spirit that defined the entire Explorer ethos from the outset.

• Case and bracelet remain in great condition, nice sharp lugs with factory brushing still visible. 
• Hairline scratches visible on both sides of the case. 
• Bracelet in good condition, minimal stretch and some hairlines present.

• Dial & hands flawless