Part 1 What they don't tell you when you buy a 2015 Seiko Prospex Marinemaster Professional 600m Spring Drive SBDB011 JDM

Regarded as a very desirable piece of jewellery among Japanese watch aficionados.

Oh! so much more! The calibre of this watch uses a GMT version of Seiko's venerable Spring Drive, an engineering breakthrough that had taken decades and hundreds of prototypes to perfect.

Warning: The following only good for non Spring Drive knowledgeable readers...

What is Spring Drive? Oodles of fun for me every time I visualise.

Winding the watch. The mechanism allows me to enjoy time with quartz accuracy using kinetic energy stored in a conventional watch spring wound either manually using the crown or automatically by the rotor via Seiko's 'Magic Lever' arrangement.

Pic from the web.

Pic from web. Left wheel attached to rotor may spin either way while the right wheel will only rotate in one direction. That is the magic.

As the spring unwinds through the train of geared wheels, a spinning permanent magnet wheel generates electricity through the double coiled pieces powering up a Tri-synchro regulator(coils, IC, quartz combo) which

Pic from web. Round wheel has a permanent magnet. Generates(electricity), measures(tachometer) and regulates(electromagnetic brake). The spinning of the round wheel generates electricity to power IC, quartz and electro-magnet to do all the work of regulating(braking) with timing signals coming from the quartz. Yes, as the spring unwinds watch would always run faster requiring braking to control its accuracy.

Pic from web. Look Ma! No batteries!

Pic from web. Words of comfort. Without the Tri-synchro regulator watch spring would just unwind a lot faster initially and perhaps slower as the spring stored potential energy drops, but never slower than accurate time, requiring braking to give good time! Only comes to a standstill when spring fully unwound.

measures and regulate the revolution rate of that wheel, in replacement of a conventional Balance/Escapement wheel, delivering true glide motion smoothness seen through the seconds hand.

Takes my breath awaaaay, aaaaaaaay, aaaaay :-)!

The unsuspecting owner can read about it here: Seiko's Spring Drive

The model I'm tallking about is the 2015 50th Anniversary reissue of the Seiko model no. SBDB001 now known as the SBDB011(New Diamond Shield coating + Prospex Logo on crown).

Thong Sia in Malaysia carries this JDM(Japan Domestic Model)!

The distinguishing mark is the Prospex logo on the screw cap of the new SBDB011(Year 2015) versus the 'S' on older SBDB001(Year 2005). Brightz Titanium as before but coated with Diamond Shield(another Seiko coating).

I've checked the web and there isn't much detailed reviews of this watch as yet. One pretty detailed review I've found was:

Review of SBDB011

Go for it for a good review. Other reviews are basically short snippets.


Ok, I'm not going to do a review but to point out certain aspects of the watch that are not documented by Seiko unless one buys Ikuo Tokunaga's collectible books on the design aspect of Seiko watches, many of which Tokunaga himself was responsible for whilst attached as an engineer with Seiko. You'll have to read Japanese though or decipher info from the many pictures in the books of which I'm yearning to acquire myself soon!

This tells me Tokunaga has a lot to do with the older SBDB001 now the SBDB011(2015). This book is possibly out of print and one may still search for it on amazon.co.jp . I, when I get mine ,will definitely do a review.

This would be Ikuo Tokunaga's latest book. On my list to get!

All that I will share are actually available online and this blog just represents my personal discovery of the watch.

1)

The first thing you'll need to do is to adjust the bracelet to fit your hand.

Picture from the web. Seiko uses the pin and collar system to lock their bracelet links together!

Picture is from web and not representative of the SBDB011 link but a good illustration. Be careful as you push out the pin from the arrow symbol side! Hidden in blue color is the retaining collar.

Picture from the web. This link shows that a larger diameter hole fits the collar loosely.

Easy to use a small diameter (say a paper clip) pin to push it out when braced against a table top. Collar fits loosely and will fall out easily. So be careful not to lose it!

As a note, Seiko gives you 6 links on each side(2 meant for adjustments) of the bracelet from the factory. I, of my own opinion, found it best to remove only links from the side closest to your chest when reading the time. This balances the location of the watch and clasp best. I took off two links on mine!

Crown on top. This is my adjusted bracelet.

A micro adjustment of 4 holes is available on the top clasp.

Micro adjustment of 4 holes for a finer fit to your hand. Press in the pin partially and slide it to the next hole closest. Repeat for other side.

2)

The next small mystery has to do with the clasp's divers extension. By the way, the Seiko uses a tri-fold clasp system with double locks. When taking off the watch locks, the first lock is the small fold-over security latch with the Seiko logo imprinted on it. Next, pressing in the buttons on the sides of the top clasp releases the second lock. To use the divers extension press the security latch a little bit more in the open direction and the divers extension will slide!

Can be a bit of a problem when putting on the watch as one inevitably causes the extension to slide unintentionally. I tend to!

Pressing this fold-over security latch with my thumb lifts a lower key bar allowing the extension to slide!

Phew! enough fun for this weekend...stay tuned for Part 2! Cheers!