What happened to this caseback?

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Dan S

·Apr 28, 2026

I was browsing an auction site and saw an old Seamaster with a lovely dial. But look at the caseback! I'm not sure I've seen anything quite like it.

I've heard of people with corrosive perspiration, but this is another level.

 

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nkhandekar

·Apr 28, 2026

But just the medallion? What is going on there

 

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Porteroso

·Apr 28, 2026

Looks like the rest was possibly refinished so might have once been the whole back looking like that. Maybe a citrus farmer wore it? Who knows....

 

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southtexas

·Apr 28, 2026

some sort of sticker that has degraded?

 

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DON

·Apr 28, 2026

Acid for sweat. Way you can tell. Wear something in sterling silver. If it turns black after a few days. You sweat acid

 

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fiberguy

·Apr 28, 2026

 

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Dan S

·Apr 28, 2026

DON

Acid for sweat. Way you can tell. Wear something in sterling silver. If it turns black after a few days. You sweat acid

Understood, but that's true for every watch. Ever seen something like this?

And it's an interesting watch to think about from the value perspective, because it looks great and will probably go very cheap.

 

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Tony C.

·Apr 28, 2026·Ωf Jury member

Possibly the ring around the medallion was polished, creating artificial dissonance.

 

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DON

·Apr 28, 2026

Dan S

Understood, but that's true for every watch. Ever seen something like this?

And it's an interesting watch to think about from the value perspective, because it looks great and will probably go very cheap.

Never. I’m guessing the outside lathed?, but why not do the center to clean up.

 

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pugmania

·Apr 29, 2026

Looks like some Myan diety. People used to do that to coins, hobo art.

 

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Caliber561

·Apr 29, 2026

It's possible the original owner tried to remove the purple wax sealant that would've been on the watch when delivered with some sort of acid—Either that or the wax sealant trapped the owner's acidic sweat on the medallion's surface as it degraded. I doubt the outer rim was machined down significantly, because the flat shoulder that runs the circumference of the medallion isn't thinned out compared to other 2849s.

 

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nkhandekar

·Apr 29, 2026

There should be inscriptions on the verso of the case that say (inside a rectangle) WATERPROOF and SEAMASTER at top and bottom . They are gone, so the back of the case must have been polished a good amount.

 

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padders

·Apr 29, 2026·Oooo subtitles!

nkhandekar

There should be inscriptions on the verso of the case that say (inside a rectangle) WATERPROOF and SEAMASTER at top and bottom . They are gone, so the back of the case must have been polished a good amount.

I'm not sure that is actually true of the later hippocampus backs like this, some show Waterproof but if the medallion is there there, Seamaster in a box usually isn't. The earlier fat lugs certainly did have both though.