Grand Seiko’s SBGA229 divers’ watch combines traditional mechanical watchmaking and the precision of electronic timekeeping. This is made possible by Spring Drive technology, developed by Seiko, and the result is an authentic divers’ watch with a unique inner life. In this feature from our October 2019 issue, with original photos by Olaf Köster, we give it a thorough once-over. Grand Seiko stands at the forefront of Japanese watchmaking, and one-of-a-kind Spring Drive technology is regarded as the best that Seiko has ever produced. So it stands to reason that this innovation has joined the Grand Seiko collection, which traces its ancestry to the 1960s and to the idea that form follows function. The combination of mechanics and electronics seems perfect, but nevertheless, it took several years for Spring Drive technology to be integrated into Seiko’s exclusive line. Seiko premiered Spring Drive technology in 1999, but the lack of a sufficiently effective automatic winding system and, as a result, the short duration of the power reserve initially dissuaded the brand from incorporating the technique into Grand Seiko. Several years of further development culminated in the Caliber 9R...