Part 2 What they don't tell you when you buy a 2015 Seiko Prospex Marinemaster Professional 600m Spring Drive SBDB011 JDM

Part 2...

Hope you've enjoyed Part 1

Love watching the seconds hand glide and visualising Spring Drive's Tri-synchro regulator working hard to keep good time. The reserve power dial will only drop less than one demarcation line every morning and be filled up full(72 hours) again in less than half a day's activity wearing it.

Prospex Logo at an angle will darken.

I did have many wonderful visualisations as I gaze at the seconds hand glide motion of the Spring Drive, thinking of the Tri-synchro regulator mechanism applying perfectly timed pulses of braking currents to the electromagnets 8 times a second to keep the spinning wheel in-phase with the timing signals from the quartz.

Continuing from Part 1...

3)
What do those hex bolts do on both sides between the lugs of the watch?

Some may think the hex bolts help in securing the ends of the bracelet. Actually it does no such function.

Bracelet ends are secured via spring bars.

Until one digs up Tokunaga's book...in my case someone posted portions of it...

Pic from web. Hex bolts are secured to the middle piece jutting out in between the lugs.

Pic from web. This side view plan shows clearly that the hex bolt washers are actually retainers for keeping the diving bezel in place. So this neat feature allows owners to disassemble the innards of the bezel for cleaning. Cool! Bezel also show a groove with seal ring on the inside and I believe a detent ring spring mechanism at the bottom.

Pic from web. Much clearer illustration of the underneath of the watch bezel. The only thing not shown clearly is perhaps the  bezel ring detent spring that only allows counter clockwise rotation of the bezel.

4)
What is underneath the Bezel?

If the side plan view above doesn't say it all...the following pictures might...

Pic from web shows a new bezel ring for the SBDB001. Should be very similar to that of the SBDB011.

Pic from web. The underside reveals all I need to know as to the detent spring mechanism. The rubber O-ring seal fits into a circular groove on the inside surface of the side of the bezel.

Pic from web. My guess is that there is a detent ring spring somewhat like this piece off a Seiko MM300. 

5)
Can I fit an aftermarket strap?

Fair question...

Pic from web. The piece jutting out does not go all the way to the bottom and any strap thin/flexible enough e.g Natos should fit perfectly.

Pic from web. Natos fit ok.

6)
What about thicker straps/bracelets?

Well....a little unsightly IMO...

Pic from web. Cut, grind, do whatever and thicker straps/bracelets will still fit.

Pic from web. All things are possible to them that believeth!

Stay tuned for more on the way in Part 3...