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SBBN013, SBDX011 (1000m diver) were subjected to diving test.

SBBN013, SBDX011 (1000m diver) were subjected to diving test.

September 6th 2014

Seiko performed a diving demonstration experiment on the SEIKO 1000m diver's watch in cooperation with JAMSTEC. (JAMSTEC: Japan Agency for Marine-Earth Science and Technology)


JAMSTEC's Kaiko 7000 lives up to its as an unmanned probe by that can explore 7000m into the deep sea.


Seiko Prospex Depth Testing Movie


After careful preparation, the test begins.

It cleared a depth of 1000m without any problems. It goes down further to 2000m, then 3000m.

At 3000m, the back cover starts to give in, but the watch continues working.

The second hand on the 1000m Quartz stopped at 3,284m.
The glass cracked at 4,804m.

The second hand on the 1000m Automatic stopped at 4,299m, and the glass cracked at 5,993m.

There are no images of the cracked glass in this video.

A while after the experiment, I saw the watch that had been used in this experiment on display in a watch shop I happened to stop in at.

The shattered glass and severely dented back cover, which were unpublished in the video, tell the story of the severity of this experiment.

It is an amazing watch.


SBBN013 & SBDX011 were out of production models now.

Current models
Quartz Model SBBN013 Change to SBBN025

Automatic Model SBDX011 Change to SBDX013

Click Here
SEIKO Diver's Watch Site

 SBBN013, SBDX011 SEIKO DIVER WATCH diving test -seiyajapan


The differently colored dials are not the only differences between the SBGR051 and the SBGR053.

The differently colored dials are not the only differences between the SBGR051 and the SBGR053.

The first generation Grand Seiko SBGR001(Silver dial), SBGR023(Black dial) 

The only difference between the SGBR001 (Silver dial) and SBGR023(Black dial)  were the different dial colors.
All of the hands were finished with polish.

The second generation Grand Seiko SBGR051(Silver dial), SBGR053(Black dial) 

The black dial on the SGBR053 was switched up by giving the hands and indexes a brushed finish.
The polished needle blacked out on the black dial depending on lighting conditions. This was improved on.

The beveling on the needle was a little bit deepened compare with the SGBR051 hands in order to make it easier to see against the black letter board.

However, there is no need to worry for those of you who own the SGBR001 and SBG023. The appearance hasn't changed, but the movement research  on the 9S55 is progressing daily. 

The hairspring setting has been adjusted, the gear accuracy has been improved on with an increased oscillating angle, and has been finely tuned. In the case of the OVH, the parts have been changed out, so that it can always be in best of Grand Seiko condition.

References 参考文献、参照サイト

The SBGR001 evolved into the SBGR051 in 2010.

The SBGR001 evolved into the SBGR051 in 2010.

The SBGR001 evolved into the SBGR051 in 2010.

It changed over to a see-through back. (As you already know) 

The crown got bigger, making it easier to use.

The date font was made thicker, making it easier to see.  

The bottom of dial words (Japan 9Sxx-00X0) were made thicker.


The decorations on movement were also changed.


It also was given a 72 hour power reserve.

1. Switching over to an Automatic Winding System

The Magic Lever System has few parts, making it exceedingly durable.  Winding up the 55 hour main spring was more than efficient.

*About magiclever 


Winding up the 72 hour main spring made me realize that the magic lever system has its limits.

It switched over to the reversing pawl wheels system (is this name right?), which has an efficient winder. The Reverse wheel was made more compact to increase efficiency, and treating the watch with hard coating increased durability.

*About Reverser

The winding gears were rechecked, and were made more efficient by going back to using jewel bearings. That is why the number of jewels increased from 26J to 35J

2. Rethinking the Main Spring .

The length of the main spring (Spron510)  was lengthened to 10 cm compared to the 9S55, it was widened by 0.5 mm, and it switched over to the 72 hour power reserve. (The main spring was thinned out by 0.2 mm to make it more compact).

The  9S55 spring is 40 cm long and 0.12 mm thick.
 The 9S65 spring is 50 cm long and 0.10 mm thick.

Increasing Durability


1. Improving the Hairspring

The "Spron610" was used as materials for the hairspring. This doubled the  shock resistance and tripled the anti-magnetization. 

2. Improving the balance wheel


The balance wheel mortice was changed from 0.07 mm to 0.08 mm to increase durability.

3. Improving the gears

The gears were given a hard coat finish, and some gears were gold-plated with low abrasion resistance to aim for accuracy, making them more durable.




The Seiko Railway Watch

The Seiko Railway Watch

Japan's railway train conductors use railway watches, even today.


The train conductors are responsible for always keeping a watchful eye on the front of the train. That is why they use Seiko's railway watch, which is bigger than a wristwatch, has easy to see numerals, and can always be set into the same spot.


The time on this railway watch is correctly adjusted by the crew in front of a supervisor.


The watch often falls and gets hit since the driver's seat sways a lot. That is why it is made of hard-to-break acrylic. It would easily crack and shatter if it used glass.


The driver's seat is subjected to a lot of magnetism, so they can't use a radio watch. If a radio watch were to be affected by the magnetism during reception, then it would not be able to receive signals correctly.


Even quartz is weak against strong magnetism, so it is made with stronger anti-magnetic properties than regular watches.



Regular Antimagnetic Watch

Seiko Railway Watch
MAGNETIC RESISTANT 16000A/m = 200 Gauss

Grand Seiko Quartz
SBGX091 SBGX093 40,000 A/m= 500Gauss 

Grand Seiko Automatic
SBGR077 SBGR079 80,000 A/m= 1000Gauss 

Rolex Milgauss
80,000 A/m. = 1000Gauss (This is in a league all of its own, which is pretty impressive.)


 Type Magnetism resistance
(in case of direct
current magnetic field)
Common timepiece Up to 1,600 A/m
(approx. 20 gauss)
The minimum magnetism resistance requirement for a watch. (For reference)
Type 1 antimagnetic watch
(magnetic resistant watch)
Up to 4,800 A/m
(approx. 60 gauss)
A magnetic resistant watch almost always maintains its performance when placed at 5 cm from magnetic field generating devices of everyday life.
Type 2 antimagnetic watch
(super magnetic resistant watch)
Up to 16,000 A/m
(approx. 200 gauss)
A super magnetic resistant watch almost always maintains its performance when placed at 1 cm from magnetic field generating devices of everyday life.




Information source

East Japan Railway Company

Reference URL
Japan Clock & Watch association