International Watch Co., Schaffhausen, Mark XI. Made for the Australian Air Force in 1957 with case back engraving: G6B / 346 and 4X / 57. 

Case: Two-body, brushed, concave lugs, soft iron core to provide an antimagnetic shield, screwed-down case back engraved with "Broad Arrow" and marked "G6B/346, 48/57."

Dial: Original dial factory refurbished by IWC with white painted Arabic numerals and luminous coated geometrical markers, "Broad Arrow" and "T." Luminous steel bâton hands.

Movement: Cal. 89, rhodium-plated, 17 jewels, straight-line lever escapement, monometallic balance, shock absorber, self- compensating Breguet balance spring, index regulator.

Dial, case and movement signed.

Movement Number: 1371XXX RAAF Issue Nr 4X/57

Circa 1957

Diameter: 36mm Thickness: 13mm

With IWC Certificate and Service papers.

More about IWC:

With the wide array of pilot’s watches being produced in the 1930’s, the IWC Mark series are some of the most famous. The first of the IWC Mark series, Mark IX, was produced in 1936, and known as the “Spezialuhr für Flieger” or “Special Pilot’s Watch”. It featured a black dial, luminous hands, and a rotating bezel for measuring up to one hour of elapsed time. The movement was a caliber 83, which was shock-resistant and adjusted to extreme temperatures. The model was not actually known as the Mark IX until the next watch in the series was produced and designated the Mark X by the British Ministry of Defense, thus its predecessor became known as the Mark IX.

The Mark XI was introduced to the RAF in 1948, it is the most well-known watch in the Mark Series. The watch was manufactured based on the British Ministry of Defense specifications. The watch featured a soft iron dial and dust cover to shield it from magnetism. It is also fitted with the legendary IWC calibre 89, an extremely robust and reliable movement.

The watch was issued to the (British) Royal Air Force, the Royal Australian Air Force,  briefly to the South African Air Force but also to the British Overseas Airways Corporation and some were sold to civilians.

The above watch was issued to the Royal Australian Air Force in 1957. The RAAF used a precursor “G” in their numbering system for their issued equipment.  

This IWC Mark XI is in outstanding condition and is accompanied by a certificate of origin to confirm its pedigree.