Release: Grand Seiko Professional Diver’s 600m
With New Spring Drive Movement - It's Everything You Asked For!

(Grand) Seiko just released a ton of beauties on the watch world, we’ll cover them all but decided to start with the new release tied to the new Spring Dive calibre. Why? Because it seems Grand Seiko listens to you, and has just given you everything you’ve been asking for in this new Spring Drive movement. A more precise, an even more powerful and yes – an slimmer Spring Drive calibre. The first model to carry this movement is a not unfamiliar looking Professional Diver 600m.

I’m a huge fan from anything related to the existing 9R6 Spring Drive caliber. “In comparison to the 9R6 caliber that is the mainstay of the current collection, Caliber 9RA5 delivers a five-day power reserve, an increase of 60%. Its monthly precision rate has risen from ±15 seconds a month to ±10”. My only desire for the Spring Drive caliber was that I always wished it could just be a bit thinner, nothing crazy ultra slim, just a little bit thinner. And guess what, the thickness as been reduced from 5.8mm to 5.0mm. Oh yes. 

How did they manage you ask? Grand Seiko clarifies: “Caliber 9RA5’s thin profile is made possible by the re-design and re-positioning of the Magic Lever. Developed in-house in 1959, the Magic Lever boosts the efficiency of the automatic winding mechanism by using the energy created by movement of the oscillating weight in both directions.

In the new caliber, the new Offset Magic Lever is positioned away from the center of the movement to reduce its thickness. Remarkably, this is achieved with no loss of winding efficiency. The stem and crown are also positioned towards the back of the case to lower the center of gravity and achieve a comfortable fit on the wrist”.

With the movement getting slimmer, this also impacts the toughness of the movement. In order to ensure this can take a beating and would meet the standards to qualify in a professional diver’s watch they redesigned the bridge. This One-piece Center Bridge achieves a shock resistance that meets the ISO standard for diver’s watches.

The movement is slimmer, more powerful and more accurate. While I’m sure we will as a result see thinner Spring Drive watches on the market in the future, Grand Seiko decided to package this in a watch that can survive pretty much anything. A way to essentially prove that he caliber is built to last and up to the task. As a result, we are presented with a beautiful (and big) Professional DIver’s 600m. 

It has helium and water resistance that meet the challenge of saturation diving at depths of up to 600 meters. The case is in high-intensity titanium, which is 40% lighter than steel and more impervious to scratches. The power reserve is at the 10 o’clock position and the indicator is divided into five parts to show exactly and clearly how many days of power are left. The case, crystal and bezel are all designed for easy and safe disassembly for the maintenance that a professional diver demands. 

DETAILS:

Grand Seiko 60th Anniversary Limited Edition, Professional Diver’s 600M

Spring Drive 5 Days Caliber 9RA5
Driving system: Automatic
Power reserve: 5 days (120 hours)
Accuracy: +/-0.5 seconds per day (+/-10 seconds per month)
Number of jewels: 38
Diameter: 34.0mm, Thickness: 5.0mm

Specifications
High-intensity titanium case and bracelet
High definition sapphire crystal
Screw-down crown, screw case back
Water resistance: 600m saturation diver’s
Magnetic resistance: 4,800 A/m
Diameter: 46.9mm, Thickness: 16.0mm
Three-fold clasp with push button release, secure lock and extender
Approximate recommended retail price in Europe: €11,500
Limited edition of 700

  1. Great specs on the new movement and it is a beautiful diver n watch, but if only GS would decrease the size to say sub 44mm diameter and ~14mm thickness, I get the feeling it would be selling like hot cakes and will be a shortage of supply vs the fake supply shortage of a certain watch brand!

    1. Agreed! The day they release something similar spec but at 42mm – they will wonder what to do with all the money the watch community will be throwing at them..

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