Precista Royal Navy Diver (6645-99-757-3314) “Sterile Case Back”, 1990s

Dealer description — Craft & Tailored

Precista occupies an interesting and often overlooked position in the history of British military watches. Originally associated with the British watch and clock supplier Southern Watch & Clock Supplies Ltd., the company was among a relatively small group of manufacturers that produced watches for the British Ministry of Defense, including general-service watches and purpose-built divers for the Royal Navy. While Precista's military diving watches can be traced back to the early 1980s, the present watch belongs to the later generation of quartz-powered divers produced during the late 1980s and early 1990s. These watches followed the utilitarian requirements that had come to define the British military dive watch: a stainless-steel case with fixed strap bars, screw-down crown, rotating timing bezel, highly legible matte-black dial, and tritium luminous material identified by the circled "T" prominently displayed on the dial. There was little here that wasn't dictated by function. The present example carries NATO Stock Number 6645-99-757-3314 , an NSN associated with British military quartz diving watches and found on documented Royal Navy-issued Precista examples from the period. Unlike many surviving examples, however, this watch is unusual in that its case back carries the NATO Stock Number without the individual issue and year markings normally found beneath it. Issued examples are typically encountered with a sequential number followed by the year of issue, for example, documented Precista divers from 1988, 1989, and 1993 are known with this NSN and corresponding military issue numbers. Collectors commonly refer to examples such as the present watch, which lack these individual issue markings, as having a "sterile" case back . Precisely why these sterile examples exist is less clear. They may represent unissued contract watches, replacement or service stock, or watches that otherwise remained outside the normal individual-issue marking process. Without surviving documentation connecting this particular watch to one of those scenarios, however, we prefer not to speculate beyond what can be established from the watch itself. What remains is an exceptionally well-preserved example of a lesser-known British military diver of the period. Its matte-black 3-6-9 dial, oversized circled "T," sword-shaped hands, fully graduated bezel, fixed bars, and bead-blasted case give it an unmistakably military character, while its scarcity relative to the considerably better-known CWC divers makes the Precista a fascinating component of the post-MilSub Royal Navy dive-watch story. SPECS Stock # PRRNDST Brand Precista Style Military Diver Model 6645-99-757-3314 Serial N/A Size Men's Material Stainless Steel Dial Matte Black Millimeters 39.5 Strap New Phoenix Admiralty Grey Strap CASE & BRACELET The case remains in sharp and unpolished condition, retaining the original bead-blasted matte finish. The fixed strap bars remain fully intact, showing no evidence of bending or damage. The original bezel and fully graduated insert remain in sharp condition, with no major fading or marks, and the tritium lume pip is fully intact. The screw-down case back retains legible NATO NSN numbers, but the case back is free of an issuance number, and this is commonly referred to as a "sterile case back." This example also retains its original mineral glass crystal, free of scratches or blemishes. The watch will come with a new gray Phoenix strap. DIAL & HANDS The original matte black "Circle T" dial remains in perfect vintage condition; under magnification, it shows no marks or blemishes. The tritium lume on both the dial and hands has aged evenly to a rich custard-like patina. When examined under ultraviolet light, the original tritium lume on the dial and in the hands exhibits no evidence of lume degradation or prior repairs. ACCESSORIES None. The watch is running exceptionally well and keeping accurate time. It recently received a fresh battery and a new case back gasket to ensure reliable operation. While the case retains its original water-resistant design, due to the age of the watch, we do not recommend swimming or diving with it.