Spring Drive U.F.A. Ushio 300 Diver
- Category
- Sports
- Case
- High-Intensity Titanium
- Movement
- Spring Drive Power reserve: 72 h
- Functions
- Hours, Minutes, Seconds, Power reserve indicator
- Size
- ø 40.8 mm
- Thickness
- 12.9 mm
- Water resistance
- 300 m
- Reference
- SLGB023
- Price
- 12,500 CHF
Description
This year, Grand Seiko is proud to present the Spring Drive U.F.A. Ushio 300 Diver, the brand’s first diver’s watch equipped with a U.F.A. movement, offering an exceptional accuracy of ±20 seconds per year. Ever since its first watch in 1960, Grand Seiko has always striven to create the best watches possible. Because a diver’s watch demands uncompromising performance, from precision to water resistance, creating one powered by the U.F.A. movement was the natural next step in Grand Seiko’s ongoing pursuit of excellence. The result is Grand Seiko’s smallest diver’s watch ever, and its most accurate to be powered by a Spring Drive movement.
Spring Drive U.F.A.
In 2025, Grand Seiko unveiled a groundbreaking Spring Drive movement, Caliber 9RB2. With a maximum yearly deviation of ±20 seconds, it is unquestionably the most accurate mainspring-powered wristwatch movement in history*, which is why we named it Ultra Fine Accuracy, or “U.F.A.” Powering the Ushio 300 Diver is Caliber 9RB1, a U.F.A. movement specially adapted for enhanced robustness to meet the demands of diving while maintaining the exceptional annual accuracy of ±20 seconds.
* As of June 2026, based on Grand Seiko’s research.
A timeless source of inspiration in Japan’s art and culture
The new creation strikes a perfect balance between function and beauty. The watch showcases a blue variation of the “Ushio” dial, a design theme that has been part of the Grand Seiko diver’s watch since 2022. The term ushio, which means “tide” in Japanese, evokes the waters that surround the Japanese archipelago, a timeless source of inspiration in the country’s art and culture. Combined with a gradient design, the vivid dial color emphasizes the dial pattern while ensuring the excellent legibility for which Grand Seiko diver’s watches are renowned.
Evolution 9 Collection
This diver’s watch belongs to the Evolution 9 Collection, which is guided by Grand Seiko’s design philosophy, the Evolution 9 Style. While preserving and honoring the original Grand Seiko design code, the Evolution 9 Style elevates this design language to new heights by focusing on three key pillars: aesthetics, legibility, and wearing comfort.
Supplied by the brand to the GPHG for its entry.