Is there magic in the IWW shop? This Seiko 6309 150m diver is accurate to within a few seconds a week!
I have the above International Watch Works-customized Seiko 6309. It’s been bead blasted, and has a sapphire crystal, with Plongeur hands. It was re-lumed, re-lubed, and timed. And Jack Alexyon, owner of IWW (click here to go to IWW’s website), stepped into the back room behind the curtain and did something that made it accurate to within a couple seconds a WEEK!
I know most of you won’t believe me if I tell you I have a 20-year-old+ Seiko diver this accurate. With normal wear it stays within a couple seconds of the atomic clock standard over a long period of time. I can also take it off at night if I want, and place it on a table in a particular position, and it will only lose about a second overnight, thus allowing me to keep it timed very accurately over a long period of time!
To back up my story, I’m including an ongoing video sequence of the watch against the National Institute of Standards and Technology website (click here to go to the site), as well as a poorly shot still of when I started the timing test Monday, May 28th.

Below is a 30MB QuickTime video of the watch compared to the NIST website for approximately one week. Click on the image to see the movie.
I’ll continue to update the video each morning, as time allows, to let everyone see how things are progressing.
In a recent recent addition to the video, I put the watch on the table in the “lose one second over night” position and now the watch is in sync!
Welcome to June! The watch is back at +2 seconds (which is where we started) so tonight I’ll put it on the table to drag it back a second or so..
[Monday June 4th] Over the weekend, I left the watch on the table a little too much and we’re at -4 today. So the long term results for a weeks worth of observing is -6 seconds! I’m plenty happy with the that!
[Thursday June7] Today we’re at +1 second!

Thanks for reading!



May 31st, 2007 at 8:49 am
Very nice, Larry. One could do a lot worse than using a 6309 has a “base” for modifications. Perhaps you could have IWW inscribe the dial with, “Superlative Chronometer, Officially Certified.”
May 31st, 2007 at 9:01 am
Thx, I was thinking of submitting it for any trials competitions *wink*
Last night I did the trick where I park it on the table to lose a second and now I have the watch perfectly in sync..
It’s pretty neat being the rugged 6309 as well as really accurate!
June 7th, 2007 at 10:08 am
4 Seconds! I checked it out today to see how it was doing and I was very disappointed!
June 7th, 2007 at 10:38 am
Sorry about that Pete! I’ve updated the article so you are current
June 13th, 2007 at 10:27 am
As of last night it was exactly in synch with atomic time!