Rolex Explorer II 16550 Rail Dial & Spider Dial

This Rolex Explorer II reference 16550 from 1987 is one of the rare transitional references within the Explorer II family, produced for only approximately four years. This particular example is further distinguished by two highly desirable features: a sought-after Rail Dial and an attractive Spider Dial patina.

With the introduction of the reference 16550, the Explorer II gained a true GMT function for the first time. The additional 24-hour hand could now be adjusted independently from the standard hour hand, allowing the wearer to track a second time zone with ease. At the same time, Rolex replaced the acrylic crystal used on earlier models with a scratch-resistant sapphire crystal, laying the foundation for the modern Explorer II.

The undisputed highlight of this watch is its original dial. First, it features the rare Rail Dial configuration. This designation refers to the precisely aligned spacing between the words “Superlative Chronometer” and “Officially Certified.” Found on only a small portion of the production run, this dial variation is a desirable execution of the reference 16550.

Secondly, the dial displays the highly sought-after spider dial patina cherished by vintage collectors. Over the decades, the natural ageing of the lacquer has created a delicate network of hairline cracks across the surface. At first glance the dial appears almost flawless, but a closer look reveals this fascinating pattern, which gives the watch its authentic vintage character and unique charm.

The 40 mm stainless steel case is framed by the characteristic fixed 24-hour bezel featuring the desirable Fat Font numerals. The bold and deeply engraved numerals give the bezel a particularly striking appearance and are regarded by collectors as one of the most attractive features of the early Explorer II references.

Inside beats the Rolex caliber 3085. Introduced in 1983, this automatic movement was Rolex’s first caliber with an independently adjustable GMT hand and was originally developed for the GMT-Master II. However, it was replaced as early as 1988 by the slimmer caliber 3185, making its production run relatively short.

As the reference 16550 was produced for only around three years, it occupies a special place in the history of the Explorer II and remains very collectible today.

An original Rolex Oyster bracelet accomponies the watch.

Overall this Explorer is both a fascinating collector’s piece and a reliable companion for everyday wear.

Condition Report
Dial: Excellent black Rail Dial with characteristic spider dial patina – original and matching tritium lume on hands and hour markers – signed “Rolex Oyster Perpetual Date Explorer II Superlative Chronometer Officially Certified Swiss - T < 25”.

Case: 40 mm stainless steel case in excellent condition – light signs of wear – intact numbers between the lugs – correct caseback engravings – screw-down Rolex crown – original Fat Font 24-hour bezel with light signs of wear.

Movement: Automatic Rolex caliber 3085 with independently adjustable GMT hand – timegrapher results: rate deviation +15s/day, beat error: 0.3 ms, amplitude: 298 degrees.

Bracelet: Original Rolex stainless steel Oyster bracelet, reference 78360 – light signs of wear – very little stretch – clasp code P3 (1991), end links 501 – bracelet adjustable from 17.8 to 19.9 cm.

Seriennummer: R779xxx (1987)

Int.Exe.: 45245