Omega Seamaster Aqua Terra 8500 watches: "co-axial" vs. "master co-axial" versions - key differences

The Aqua Terra 8500 was made in two versions: a "co-axial" followed by a "master co-axial".
There are some technical and design differences between the two which I discuss here, namely: antimagnetic properties, frame around date window, and hour and minute hand length. I also discuss how to tell if you older "co-axial" version comes with a silicon balance spring, a feature that was added in 2011 and is also part of all later master co-axial models.
One thing they have in common in that are both beautiful and well--made, versatile watches

[@rondurr7503]

just wanted to say thanks for your videos on the Aqua Terra. Did not know a lot about the particulars, but your videos helped make the right choice when making my purchase.

[@omegawatchfan]

Thank you! I am glad to hear it was helpful.

[@vanleuveren9675]

Very detailed and usefull information. Thank you for that! Keep up the good work...

[@omegawatchfan]

Thanks! I am glad it was helpful

[@crapmarine]

Great video, the detail about the hand length is really interesting! Are the cases identical? To my eye the older one looks to have a slightly softer outer curve in the lugs.

[@omegawatchfan]

Thank you! As far as I'm aware there was no official change to the case shape between these models, but in handling several of these watches, I have noticed some very minor variation in the case finishing and sharpness of edges, particularly on the lyre lugs.

[@crapmarine]

@@omegawatchfan Thank you!

[@jaysterling26]

Very informative, thank you. I'm looking at the 36mm model - can you tell if the co-axial version had any anti-magnetic properties? Cheers.

[@omegawatchfan]

If it is the 2500 movement (predecessor to the 8500), it does not have antimagnetic properties but does have a antimag cover between the movement and the caseback.

[@wade3mvp1]

My master coaxial model has the longer minute hand and the shorter hour hand…

[@explorerjlc1743]

This is the issue with Omega, they always look dated when a new version gets released. They make trendy designs which looks striking at first but are not timeless. Except the speedy.

[@omegawatchfan]

Part of the problem is their designs which could frequently benefit from being a bit more conservative, and another part is the frequent changes and updates they make, which causes the prior design to look dated immediately. There are some exceptions though, like you said the Speedy, I would also add the 1st gen Planet Ocean and 1st gen Aqua Terra....both are conservative designs that will last. When the 8500 Aqua Terra came out, I thought the vertical lines would forever become an iconic feature of future Aqua Terras....but just a few years later they scrapped it and changed the dial, thereby forever dating that design to a particular period.

[@explorerjlc1743]

@@omegawatchfan on the money there my man.

[@vdan2879]

No frame version my vote