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Jaeger-LeCoultre Geophysic

Geophysic was a chronometer produced by Jaeger-LeCoultre in 1958.

The International Geophysical Year spanned 1957 and 1958 and was intended to highlight scientific exploration. Numerous expeditions were launched, including exploration of the Antarctic, high mountains, and deep sea, and watches were an integral part of this. Companies like Rolex, Jaeger-LeCoultre, and Nivada produced special watches for these explorers and to commemorate their accomplishments. Generally, these were highly-accurate chronometers with anti-magnetic properties and were water resistant.

The Jaeger-LeCoultre contribution was the Geophysic. It was a certified chronometer, unusual for the manufacture, which has not produced many chronometers. The case contained a highly-accurate hand-wound movement related to the military chronometers Jaeger-LeCoultre produced in the previous decade. The case included a soft iron core to protect it from magnetism, and the dial was designed to be easily read in difficult conditions. On the back was a gold medallion depicting a “Planisphere”, a globe with latidute and longitude lines with the south pole in the lower right.

Jaeger-LeCoultre and the citizens of Geneva presented two special Geophysic sets to the Commanders of the USS Skate (Calvert) and Nautilus (Anderson) to commemorate their accomplishment of reaching and traversing the North Pole in their submarines in the summer of of 1958.

But the Geophysic was not just a scientific tool. It was produced in both stainless steel and gold, and a Deluxe model did not include the anti-magnetic case. Approximately 1,400 Geophysic watches were made and sold from 1958 through 1961. Jaeger-LeCoultre replaced the Geophysic with an automatic derivative, the Geomatic. In 2014, Jaeger-LeCoultre released the Tribute To Geophysic, a watch with the classic look of the original Geophysic but containing a modern automatic movement.

Movement and Models

All Jaeger-LeCoultre Geophysics share the same movement. Cal. P 478 BWSBr was a derivative of the Cal. 488 SBr used in the Mark 11 pilot's watch. This movement, in turn, was derived from the Cal. 470, which was used in the military Mark 7 A. Cal. 488 had added hacking seconds, and Cal. 478 included a swan neck regulator and shock protection. The version of Cal. 478 used in the Geophysic was specially calibrated and adjusted for chronometer certification.

The Geophysic was delivered in two variants

  • Ref. E 168 had a 35 mm case which included the soft iron anti-magnetic inner core, making it resistant up to 600 Gauss. It was available in stainless steel, yellow gold, or rose gold.
  • Ref. 2985, or “Geophysic Deluxe”, had a 34 mm case without the anti-magnetic properties. It was produced in yellow gold and rose gold only.

There were three dials produced for the Geophysic

  • The Ref. E 168 came with a plain dial with 12 and 6 marked in Arabic numerals, 3 and 9 marked with double bars, and all other hours marked with single bars. Each minute between was marked with a line.
  • A later “crosshair dial” was introduced for Ref. E 168 with 3, 6, 9, and 12 marked in Arabic numerals, single bars at all other hours, and an outer “track” with numbering at 5-minute intervals and minute markers between. Most obvious was the “crosshair” marks both vertical and horizontal. It is unclear if any Geophysic models included this dial from the factory or if it was a later factory replacement for the original dial.
  • The Geophysic Deluxe came with a clean dial with only 12 marked as an arabic numeral and all other hours marked with applied batons. Minute markers were placed between on the same “track”. Some Geophysic Deluxe models use the crosshair dial today, but it is unclear if this is a replacement or original spec.




  • Applied steel or gold numerals and markers
  • Black transferred lines
  • Skeleton steel or gold hour and minute hands


  • Sweep hour, minute, second hands


  • Crocodile leather strap


jaeger-lecoultre_geophysic.txt · Last modified: 02.12.2022 20:43 by

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