Arguably under appreciated, the original Ultra-Chron High-Beat Diver was a precision timekeeper with a high-frequency movement, the L.836.6. With the high-spec movement, the watch was appealing, albeit pricey by Longines’ standards. Now the brand has given the model an upgrade with the Ultra-Chron Carbon. The Ultra-Chron Carbon retains the familiar cushion-shaped case, but now in carbon composite, giving it lightness and a modern aesthetic that contrasts well with the retro, 1970s origins of the design.

Initial thoughts

The Ultra-Chron Carbon stands out for its blend of an advanced, industrial movement, composite materials technology (undoubtedly thanks to the Swatch Group’s vast industrial base), and a vintage-inspired aesthetic. Although it’s simply a modest variation of an existing model, the new Ultra-Chron marks the brand’s first venture into non-traditional case materials in the modern day.

Priced at US$4,900, the Ultra-Chron Carbon commands a notably higher price than its stainless steel counterpart. While it does offer technical advantages — such as the carbon composite case and a high-frequency (5 Hz) movement — the watch still feels a little expensive relative to alternatives, especially since Longines is primarily a brand that competes in a lower price range.

More broadly, the Ultra-Chron Carbon is not a like-for-like vintage remake, which is a good thing. But Longines can arguably do more with its movements. Given that the brand’s enthusiast-oriented offerings is dominated by vintage reissues, it would be refreshing to see Longines introduce something entirely new rather than relying on bringing back historical models.

Carbon case

Water resistant to 300 m, the cushion-shaped carbon composite case is 43 mm in diameter and 14 mm in thickness. The material contributes to the watch’s featherlight weight – only 80 g including the strap.

The composite is constructed from layers of unidirectional carbon fibre and epoxy resin, which are placed into a mould and heat-treated at a high temperature, then compressed under great pressure. The resin hardens, binding the two elements together to result in a block of composite that is machined into the case. The random arrangement of the carbon fibre layers within the resin ensures each case is one of a kind in terms of graining.

Another distinguishing feature of the Ultra-Chron Carbon is the fixed titanium bezel with a matte black aluminium insert featuring grey markings. The screw-down crown and the solid case back are likewise in titanium. The choice of a fixed bezel is curious, since it is effectively a sort of minutes ring, rather than a functional diver’s bezel.

The matte black dial has a grained finish with 12 applied indices and matching baton hands, all filled with blue luminescent Super-LumiNova. In addition, the original Ultra-Chron emblem from the 1970s is replicated right above the six o’clock marker.

Beneath the solid caseback lies the high-frequency L.836.6, which beats at 36,000 beats per hour (5 Hz) and offers 52 hours of power reserve. The power reserve isn’t the longest on the market, but respectable given the energy-intensive oscillator.

Moreover, and unusually for a watch at this price point, the movement is chronometer-certified by Timelab in Geneva. The cased watch is tested for 15 days and then certified to the ISO 3159 chronometer standard.

Like all Longines movements, the L.836.6 calibre has its roots in a basic ETA calibre but is substantially upgraded. This is derived from the ETA 2892 but features a completely reworked gear train, from the mainspring barrel to the oscillator. It sports a silicon balance spring, giving it high levels of resistance to magnetism.

While high-beat movements are generally regarded as more stable timekeepers, since the oscillator is less susceptible to shock-induced deviations, the flat hairspring is in fact more prone to isochronal defects due to its interaction with the terminal points.

The silicon hairspring was designed with an optimised geometry, guaranteeing an even development of the spiral during oscillation. The fast-beating balance is free-sprung, so the regulation holds better over time.

Key facts and price

Longines Ultra-Chron Carbon
Ref. L2.839.4.52.2

Case diameter: 43 mm
Height: 14 mm
Material: Carbon
Crystal: Sapphire
Water resistance: 300 m

Movement: L.836.6
Functions: Hours, minutes, and seconds
Frequency: 36,000 beats per hour (3.5 Hz)
Winding: Automatic
Power reserve: 52 hours

Strap: Black technical fabric strap with a titanium buckle

Availability: Now at Longines retailers and boutiques
Price:US$4,900

For more, visit Longines.com.