Longines Ultra-Chron: The World's First High-Frequency Dive Watch Returns

The Longines Ultra-Chron takes its most direct inspiration from a dive watch the brand introduced in 1968, but it also represents the culmination of Longines’ expertise in making high-frequency watch movements, which goes back more than 100 years.

Longines’ century-plus quest for high-frequency timekeeping precision started in 1914, when it produced the first hand-held stopwatches (like the one below) with movements that measured time to 1/10 second thanks to their high-frequency movement, Caliber 19.73N, whose balance wheel oscillated at 36,600 vph.

It continued with a modification of that caliber to achieve an astonishing rate of 360,000 vph, and a stopwatch accuracy of 1/100 second, in 1916; hit a new milestone with the launch of the Observatory Chronometer in 1959, the first wristwatch with a 36,600-vph movement; and culminated with the introduction of the Ultra-Chron Diver (below) in 1968, which became the world’s first high-frequency divers’ watch, housing the 36,600-vph Caliber 431. (Yes, this predates by one year the most famous high-frequency movement, the Zenith El Primero, though that movement also incorporated automatic winding and a chronograph.)

The Ultra-Chron Diver provides the template for the all-new Ultra-Chron model, whose cushion-shaped stainless steel case spans a contemporary 43mm in diameter and 13.6mm thick as well as a 300-meter water resistance — an improvement on the vintage model’s 200-meter rating. Like its predecessor, and in the tradition of most modern diver’s watches, it features a unidirectional rotating bezel whose dive-scale insert is made of sapphire, with luminous-treated accents. Both the crown and the caseback screw down securely; the latter is embellished with an engraved “ULTRA-CHRON” logo and an “ULTRA CHRONOMETER OFFICIALLY CERTIFIED” inscription. 

Also luminous-coated are the applied baton-shaped indexes on the black grained dial as well as the hands. As did many watches of its era, the original Ultra-Chron Diver used tritium for its luminous elements; its modern descendant uses the more common (and less radioactive) Super-LumiNova. Carrying over from the 1968 model is the use of bright red to distinguish the minute hand from the rhodium-plated hour hand and seconds hand. A box-shaped sapphire crystal, treated on both its surfaces with multiple layers of antireflective coating, enhances the dial’s legibility while keeping it securely covered. Setting the new watch apart from its ancestor is the lack of a date window at 3 o’clock, making for a cleaner, more balanced aesthetic.

Inside the case, beating at the 36,600-vph frequency pioneered by its 1914 predecessor, is the new in-house Caliber L836.6, a self-winding movement with a silicon balance spring and a power reserve of 52 hours. Following in Longines’ historical tradition of chronometry prizes, the Ultra-Chron boasts a certification as an “ultra chronometer” by the independent testing agency TIMELAB in Geneva. The criteria for this certification, Longines says, go beyond those required for chronometer certification by COSC, which have long been the benchmark for the watch industry. TIMELAB tests the cased movement for a 15-day period at three different temperatures — 8ºC, 23ºC, and 38ºC — to confirm that it meets the strict precision standards set forth in ISO 3159:2009.

The Longines Ultra-Chron is offered on either a stainless steel bracelet, with a double safety folding clasp, or on a brown leather strap with a pin buckle. Both versions come in a handsome wooden box (above) with an additional black NATO strap made of recycled material, along with a tool to change straps. On the bracelet, the watch retails for $3,700; on the strap, it sells for $3,500.