Jaeger-LeCoultre Mark XI (Ref. G6B/346) "Royal Australian Air Force", 1953

Dealer description — Craft & Tailored

The Jaeger-LeCoultre Mark XI was born from strict military necessity. Introduced under the British Ministry of Defence’s G6B/346 specification in 1947, the Mark XI set a new benchmark for accuracy, durability, and anti-magnetic performance in navigation watches. Produced by Jaeger-LeCoultre and IWC Schaffhausen, JLC’s run concluded in 1953—making examples like this among the last and most desirable. This watch was issued to the Royal Australian Air Force as part of the second 1953 batch, one of just 600 pieces, with correct “G6B/346,” “RA AF,” and “/53” caseback engravings. The Royal Australian Air Force-issued Mark XI distinguishes itself from its Royal Air Force counterpart through a handful of subtle but meaningful updates. Most notably, RAAF examples utilize spring bars in place of the fixed bars found on RAF-issued watches, allowing for greater strap versatility. Jaeger-LeCoultre also introduced slight variations in handsets, with this example featuring a syringe minute hand paired with a rectangular hour hand. Additionally, the RAAF models were fitted with a flat crystal rather than the domed plexiglass seen on earlier RAF pieces, a practical refinement that improves legibility while reducing glare in active use. Powering the watch is the Calibre 488/SBr, a chronometer-grade movement with hacking seconds, tested over 44 days at the Royal Greenwich Observatory, and protected by an inner iron cage for anti-magnetic resistance. Purpose-built and highly refined, the Mark XI remains one of the most important military watches ever produced; this rare RAAF example stands out for both its condition and scarcity. SPECS Stock # JLCMKXIRAAF Brand Jaeger-LeCoultre Style Mark XI Model G6B/346 Serial 33X / 91XXXX Size Men's Material Stainless Steel Dial Matte Black Millimeters 36 Strap Vintage Blue Phoenix NATO Strap CASE & BRACELET The wonderful fixed spring bar case, featuring elongated lugs, displays minimal evidence of prior polishing, with light signs of honest wear. The flat crystal is original to the watch and exhibits light crazing. The unsigned crown is believed to remain original to the watch. The case back displays all of its military markings in deep, legible condition, with some minor tool marks present. The watch comes supplied on a vintage Phoenix NATO strap. DIAL & HANDS The matte black dial is remarkably well-preserved, only showing light aging in the form of speckling and some minor stains, though no actual damage is present. The white Arabic numerals and text are in excellent condition and remain bright. The radium markers have developed a vivid orange "pumpkin" patina and exhibit no notable degradation when inspected under UV light. The original hands have been professionally restored to match the patina of the dial. ACCESSORIES None. The watch is keeping time perfectly, previous service history is unknown.