Hands-On Exclusive: Longines Debuts Ultra-Chron Carbon High-Frequency Diver

Just over two years ago, Longines launched the Ultra-Chron, a revival of the super-accurate 1968 original that gained notoriety as the world’s first high-frequency diver. Now Longines has released the Ultra-Chron Carbon, which is the brand’s first watch with a case made from carbon fiber, which, of course, is known for its lightweight durability. The watch, in fact, comes in at just 80 grams for the case and strap.

The original Ultra-Chron Diver Ref. 7970 from 1968 was a cushion-cased steel watch that measured 41mm wide with 200 meters of water resistance. It was outfitted with the 5Hz Caliber 431 movement, which was accurate to 2 seconds per day. Our resident expert Mark Bernardo went into all the details of this model as well as the brand’s history with high-frequency timekeeping, in an article you can read here. 

The 2022 revival was a little bigger, coming in at 43mm wide, but also beefed up the water resistance to 300 meters. This new Ultra-Chron Carbon shares the same basic specs as this revival model but the blacked-out design kind of makes all the difference in terms of style versatility. Rather than a red minutes hand and matching red accents on the bezel, we see a sleek, monochrome aesthetic that is more stealth than sporty. The use of a contemporary material like carbon also offsets some of that overt “vintage-inspired” design language in favor of its own identity.

The cushion-shaped case measures 43mm wide and 14mm thick with a 48mm lug-to-lug measurement, according to my calipers. The central case band, done in that recognizable horizontal carbon fiber pattern, looks excellent and will be slightly different on each watch since no two can be the same. The enclosed caseback, crown, and bezel, and the strap's buckle, are done in titanium, which helps keep the weight down without compromising toughness and durability. While on the topic, it’s worth noting that the Ultra-Chron Carbon bezel is fixed with an aluminum insert, making it distinct from the rotating sapphire crystal bezel of the 2022 model. Personally, I think the matte finish of aluminum fits much better with the identity of this watch. Finally, there is the black, technical fabric strap which has a leather inner lining. I have to say, it’s really lightweight and comfortable to wear.

Dial legibility is excellent, and I was very pleasantly relieved seeing the watch in person because I did have an initial concern about that, due to the grey-PVD- coated hands against the sandblasted anthracite dial. Dark hands on a dark dial can be tricky to pull off, but the large blocks of lume help quite a bit, as does the beveling on the polished hands. The applied hour indices are done in a slightly lighter silver that helps provide just enough contrast, and are bolstered with a healthy treatment of lume as well. Finally, the anti-reflective coating on the sapphire crystal goes a long way to aid in legibility.

The exclusive Longines Caliber L.836.6 movement is a TIMELAB-certified chronometer that keeps well within the ISO 3159 standard, which involves a 15-day testing period in which the watch is put through a series of tests in various positions at temperatures of 8°C, 23°C and 38°C. The L.836.6 operates at 5Hz (36,000 vph) and has a 52-hour power reserve. Also of note is the silicon balance spring (thanks to Longines having the resources of the Swatch Group) which helps with accuracy and allows for a 5-year guarantee from the brand.

The Longines Ultra-Chron Carbon is priced at $4,900 and comes in a special black presentation box that ties together the sleek and brooding monochromatic color scheme. Indeed, this is a premium over the stainless-steel version but that is to be expected with a carbon fiber case. You can learn more about this watch at longines.com.