Grand Seiko 60th Anniversary Limited Edition Professional Diver's 600M SLGA001 The Grand Seiko Sport was… not quite a leap for the brand but at least a step into the unknown for a brand that had generally stuck to restrained, classic beauty. Now they’re finishing their transition with the new Grand Seiko 60th Anniversary Limited Edition Professional Diver’s Watch 600M.

The SLGA001 is Seiko’s first professional dive watch to house their Spring Drive movement, which means, on top of the usual necessities: rugged case, unidirectional diving bezel and a solid depth resistance, you also get incredible accuracy, thanks to the quartz-mechanical hybrid movement.

The huge 46.9mm case is made from high-intensity titanium, double the hardness of steel with all the lightness of standard titanium. The same goes for the chunky bezel which, this being Grand Seiko, you can be sure is fantastically robust. So far, so overachieving. But then there’s the water resistance.

Grand Seiko 60th Anniversary Limited Edition Professional Diver's 600M SLGA001

Rather than the usual 300m for a professional diver, Grand Seiko has gone all the way to Planet Ocean levels of depth resistance at 600m. Combined with plenty of lume and a screw-down crown – in typical Seiko fashion it’s at 4 o’clock rather than 3 – this has everything a serious depth-dweller could want and more.

That’s not the end of what makes the new diver special though. This is the first watch to house Grand Seiko’s new 9RA5 calibre, the latest generation of the watchmaker’s lauded Spring Drive movement.

Grand Seiko 60th Anniversary Limited Edition Professional Diver's 600M SLGA001

The advancements are pretty substantial. It’s thinner, though you might not notice in this particular watch; it has a phenomenal 120-hour power reserve and it has significantly improved shock resistance. It’s even more precise, thanks to new circuitry monitoring the temperature of the movement. The result is a movement that gains or loses just 10 seconds per month, or 0.5 seconds a day.

The Grand Seiko Diver is limited to just 700 pieces and will be available from August, but you can expect to see the new 9RA5 calibre in other Grand Seiko pieces before then.

Price & Specs:

Model Name: Grand Seiko 60th Anniversary Limited Edition Professional Diver
Ref: SLGA001
Case/Dial: 46.9mm diameter x 16mm thickness, high-intensity titanium
Water resistance: 600m (60 ATM)
Movement: Caliber 9RA5, Self-Winding (Spring Drive)
Functions: Minutes, hours, date, power reserve
Frequency: 28,800 vph (4 Hz)
Power reserve: 120h
Strap: High-intensity titanium bracelet, blue silicone
Price: €11,500, limited to 700 pieces worldwide, available in August

More details at Grand Seiko’s website.