Debuting in 1967, the Ultra-Chron was created as part of Longines’ centenary celebrations and marked the brand’s push to have the first mass-produced high-frequency precision watch.

Produced for only six years, the original Ultra-Chron was promoted with a guarantee that its accuracy was within one minute per month, achieved through the use of a patented dry lubrication system which allowed the high-frequency movement to operate smoothly and consistently. The lubricant – molybdenum bi-sulphide, solved the friction issue that had troubled the early hi-beat movements.

Advertisements touted the Ultra-Chron as being “the world’s most accurate watch”, promoting the 36,000 VPH hi-beat Cal. 431 movement, but there were a couple of different movements used in the model during its lifespan such as the Cal. 430 (centre seconds), the aforementioned Cal. 431 (centre seconds and date), Cal. 432 (time-only), Cal. 433 (date), and some manually-wound movements.

In 1968 Longines introduced the Ultra-Chron Diver (Ref. 7970). The first high-frequency diver’s watch, it came in a 41 mm stainless steel cushion case with a screw-down case back and water resistance of 200m. The high frequency movement used was the Cal. 431.

It wasn’t until 2022 that Longines decided to revive the Ultra-Chron name, with a new model that was a nod to the 1968 Ultra-Chron Diver in a cushion-shaped stainless steel case a more modern 43mm, and with water resistance increased to 300m.

Now, the twenty-first century Ultra-Chron finds itself clad in carbon. This is also the first time that Longines have used it as a case material.

Measuring 43mm, at 14mm thick with a screw-down titanium crown it is 0.1mm thicker than the 2022 stainless steel Longines Ultra-Chron. The case is made from strips of unidirectional carbon fibre and epoxy resin which are placed into a mould and heated to a high temperature, compressed under high pressure, then cold-cut into the required shape. There is a fixed titanium bezel with an aluminium insert. It still retains the same 300m water resistance.

Beneath a sapphire crystal is a sand-blasted anthracite dial with a chapter ring with applied silver indicies and minute numbers. The hour and minute hands are grey PVD and have blue Super-LumiNova. The original Ultra-Chron logo is used for this model, which is applied to the dial.

As with the stainless steel model, the Ultra-Chron Carbon is powered by the TimeLab chronometer-certified high-frequency L.836.6 beating at 36,000 VPH with a power reserve of 52 hours.

Coming on a black technical fabric strap with a titanium buckle, the new Longines Ultra-Chron Carbon weighs less than 80g in total, strap-inclusive.

[Photo credit: Longines]

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