Nivada Grenchen F77 MK2 Open Heart Titanium 38mm 68023A77

The Nivada Grenchen F77 MK2 Open Heart Titanium Ref. 68023A77 takes the brand’s revived 1977 integrated-bracelet sports watch and gives it a distinctly more modern, technical character. The MK2 uses a redesigned 38mm case measuring 46.2mm lug-to-lug and 12.2mm thick, with more curved lugs and improved ergonomics compared with the earlier F77 revival. For the Open Heart edition, the case is crafted from lightweight Grade 5 titanium with alternating brushed and polished surfaces, retaining the F77’s signature octagonal bezel and architectural 1970s-inspired profile. The fractured open-heart dial exposes the mechanical balance at 6 o’clock, creating a direct view into the movement while applied indexes and luminous accents preserve everyday legibility. A double-domed sapphire crystal, screw-down crown, sapphire exhibition caseback, and 100 meters of water resistance round out a package that blends vintage integrated-sports-watch styling with contemporary materials. Nivada Grenchen
Visible from both the dial and caseback is the Swiss-made SOPROD M100BV automatic movement, derived from the proven A10 architecture. The 25-jewel caliber operates at 28,800 vibrations per hour and delivers approximately 42 hours of power reserve, with its balance, bridges, gearing, and automatic winding rotor placed on display through the watch’s open construction. Nivada Grenchen The F77 itself traces its design back to Nivada Grenchen’s original 1977 sports watch, recognizable for its integrated construction, faceted case, and distinctive octagonal bezel. The MK2 Open Heart pushes that formula in a more technical direction, with Grade 5 titanium significantly changing the feel of the watch while the exposed mechanical architecture adds depth absent from the traditional F77. With its compact 38mm proportions, titanium construction, open-heart dial, exhibition back, and Swiss automatic movement, the 68023A77 is one of the most contemporary interpretations of Nivada Grenchen’s revived 1970s design.

Reference: 68023A77

Bracelet: Titanium

Case: 38mm x 11.5mm Thickness x 46.2mm lug to lug - Titanium

Lug Width: 22mm

Movement: Soprod M100BV - Automatic

Dial: Black Braided Open Heart Dial

Functions: HMS

Box and Papers: Inner/outer boxes, and warranty card

Crystal: Double Domed Sapphire

Bracelet size: 7.75"

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Nivada Grenchen, established in 1926 in Grenchen, Switzerland, quickly became renowned for its rugged tool watches that pushed the boundaries of horological innovation. The brand solidified its reputation with the introduction of the Antarctic in 1950, the first waterproof automatic watch. This timepiece gained fame when it accompanied members of the U.S. Navy's Operation Deep Freeze I during their South Pole expedition from 1955 to 1956.



In 1961, Nivada Grenchen launched the Chronomaster, a versatile waterproof chronograph designed for aviators, divers, and sports enthusiasts. The company continued its innovative streak with the release of the Depthomatic in 1964, the first diver's watch featuring a depth indicator, followed by the Depthmaster in 1965, capable of withstanding pressures up to 1,000 meters.

After a period of dormancy, Nivada Grenchen experienced a rebirth in 2018, reintroducing two of its most iconic models—the Chronomaster Aviator Sea Diver and the Antarctic—at the forefront of its revival. The relaunch paved the way for the brand’s enduring appeal among modern watch enthusiasts while honoring its storied heritage.