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

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.