Grand Seiko SLGB006 "Dawn of the Ice Forest" and the World's Most Precise Spring-Driven Movement at Watches & Wonders 2026
At Watches & Wonders 2025, Grand Seiko unveiled a groundbreaking automatic watch with a significant breakthrough in timekeeping accuracy: the 9RB2 automatic movement, which the brand claims is the most precise in its class. A year later, at Watches & Wonders 2026, this movement will debut in a limited-edition watch with a gold case—the first time this movement has been made in gold. The dial design is inspired by the snow-capped forests of Shinshu, the region where the movement was born. We will now take a closer look at the Grand Seiko SLGB006 "Dawn of the Ice Forest" watch and its 9RB2 movement. http://www.moon-watch.co.uk
The Spring Drive 9R65 Movement: The World's Most Precise Spring-Driven Movement
Grand Seiko patented the Spring Drive movement in the late 1970s and first introduced it in 1988. This movement employed a completely different regulating system from its Swiss counterparts' mechanical systems. It lacked a traditional escapement, instead using a pulley system regulated and braked by a quartz oscillator and electronic control circuitry. Notably, the entire Spring Drive system required no battery; the quartz module was entirely powered by the mainspring. In 2004, this technology reached its zenith with the introduction of the Spring Drive Calibre 9R65 movement. This movement differed significantly from the brand's previous movements: it not only featured automatic winding and a 72-hour power reserve but also a regulating system capable of achieving an accuracy of ±15 seconds per month.
In 2025, at Watches & Wonders, Grand Seiko unveiled another major innovation to its Spring Drive movement: the Calibre 9RB2, an automatic movement with a 72-hour power reserve, also featured in the new Grand Seiko SLGB006 "Ice Forest at Dawn" watch. The Calibre 9RB2 is named "Spring Drive UFA," where "UFA" stands for "Ultra Fine Accuracy." Its accuracy is ±20 seconds, not daily, weekly, or monthly, but annually. With this high level of precision—equivalent to approximately ±3 seconds per month, 12 seconds more accurate than its predecessor—Seiko claims to have developed the most accurate mainspring-driven movement to date. https://www.whereguidewatch.com
This ±20-second-per-year (approximately ±3-second per month) precision is achieved through a self-developed quartz crystal oscillator whose frequency has been stabilized over a three-month period. Afterward, the oscillator is vacuum-sealed with a newly developed energy-efficient integrated circuit to minimize external interference. Temperature compensation also plays a crucial role: before assembly, each quartz crystal is measured at different temperatures, allowing the movement to compensate for even the smallest temperature variations that would otherwise affect its accuracy.
The Design and Construction of the New Seiko Grand Seiko SLGB006 “Dawn in the Snowy Forest” Since 2004, Spring Drive watches have been meticulously crafted by watchmakers at the Shinshu Watch Workshop in Shiojiri City, Nagano Prefecture. Here, in these highly functional workshops, every hour marker is hand-set onto the dial, every 9R series Spring Drive movement is handcrafted by skilled artisans, and every case is polished to a mirror-like finish according to the principles of the Zaratsu polishing technique. The Shinshu Watch Workshop is located in the mountainous region of Japan, known for its harsh winters, and this harsh winter is the inspiration for the “Ice Forest” dial design of this new watch. Not far from the workshop lies the Kirimine Plateau, renowned for its "Ice Forest." In the exceptionally cold winter, larch trees are blanketed in snow and ice, shimmering in the morning sunlight. Grand Seiko cleverly captures the winter beauty of the Kirimine Plateau with its "Ice Forest" dial. Its design concept originates from the Japanese principle of "mitate," which interprets the scene not through direct depiction, but through color, form, and surface texture. The Grand Seiko SLGB006 "Ice Forest Dawn" watch features a finely textured dial with subtle gradients within a deep black tone, adorned with numerous reflective particles. Gold hour markers and hands contrast sharply with the dark dial, aiming to evoke the warm hues of a rising sun.
This Grand Seiko SLGB006 "Ice Forest Dawn" watch, with a diameter of 37mm, is the first timepiece of its size in the Evolution 9 series to be crafted in 18K gold. It features a black alligator leather strap and a matching gold triple-folding clasp with a push-button release mechanism. The case is 11.4 mm thick and has a screw-down sapphire crystal case back. It is water-resistant to 100 meters (10 bar). https://www.chronowrist.ru

