Does anyone own a 90's era Seamaster 120m - Model 2511.XX? Measurements needed

502 to right · Mar 11, 2026

I'm thinking about picking up a 90's era Seamaster 120m. Specifically, the quartz version which is the model 2511.XX. This is the predecessor to the Aqua Terra. The problem is I can only find them online and really need to know how the size would compare to my 36.2mm Aqua Terra.

If anyone has one of these (either quartz or automatic as long as it's the 36.25mm case), could you let me know what the crystal measures edge to edge? And also the outside dimension of the bezel? It looks to me like the bezel is wider than the Aqua Terra 36.2mm, which would make the crystal smaller.

Thanks!

Archer · Mar 11, 2026

I don't have one, but looking on the Extranet at a 25118100 - blue dial quartz version that appears to match your photo, I see some possibly helpful information.

The case is listed at 38 mm in diameter, with 18 mm lug width.

The crystal diameter is 28.5 mm.

The bezel diameter is not listed.

The dial diameter is listed at 28.5 mm.

When I compare this to an AT quartz, like ref. 25185000, there are some differences:

Case diameter is listed at 36.2 mm.

Dial is listed at 28.5 mm, so the same as the other model.

The crystal is listed at 30 mm, so larger than the other model.

So the AT is smaller, but with the same sized dial, and larger crystal, which would make the dial look larger.

Hope this helps.

502 to right · Mar 11, 2026

Archer
I don't have one, but looking on the Extranet at a 25118100 - blue dial quartz version that appears to match your photo, I see some possibly helpful information.

The case is listed at 38 mm in diameter, with 18 mm lug width.

The crystal diameter is 28.5 mm.

The bezel diameter is not listed.

The dial diameter is listed at 28.5 mm.

When I compare this to an AT quartz, like ref. 25185000, there are some differences:

Case diameter is listed at 36.2 mm.

Dial is listed at 28.5 mm, so the same as the other model.

The crystal is listed at 30 mm, so larger than the other model.

So the AT is smaller, but with the same sized dial, and larger crystal, which would make the dial look larger.

Hope this helps.

Thank you. That does help. All references I see online show the 2511.XX to have a 36.25mm case. But the key measurement I'm looking for is the crystal. I don't want a watch that looks smaller than the 2518.80 Aqua Terra I already own. I have the quartz 36.25mm SMP and the small dial and crystal make it looks really small. I suspect Omega made the 36.25mm SMP and the 2511 with the same case but one with a rotating dive bezel and one with a smooth bezel.

That said, my biggest issue with the 2518.80 Aqua Terra is that the hands disappear against the dark blue dial--especially the minute hand since it doesn't have white lume running down the length of the hand. If I wasn't in my 50's that probably wouldn't be an issue.

But if the 2511 has the same size dial as the AT, I could buy one like the one below (2511.83), and swap the dial and hands into my AT. I love the AT case shape and size, but the hands are killing me right now.

As an alternative, I could source some 1.20/0.70 hands with better lume (for a greater contrast against the blue dial) and have them installed on my AT. I'm searching now.

502 to right · Mar 11, 2026

The more I think about it, the more I think buying a set of hands with better lume/contrast is the way to go. It will be much cheaper and easier. But I would need to find some high quality hands.

502 to right · Mar 11, 2026

I found some new TAG Heuer hands with good contrast that should be the proper size for the AT. Like the ones below. I should be able to continue to use the AT seconds hand, which has good visibility.

ErichPryde · Mar 11, 2026

502 to right
Thank you. That does help. All references I see online show the 2511.XX to have a 36.25mm case. But the key measurement I'm looking for is the crystal. I don't want a watch that looks smaller than the 2518.80 Aqua Terra I already own. I have the quartz 36.25mm SMP and the small dial and crystal make it looks really small. I suspect Omega made the 36.25mm SMP and the 2511 with the same case but one with a rotating dive bezel and one with a smooth bezel.

That said, my biggest issue with the 2518.80 Aqua Terra is that the hands disappear against the dark blue dial--especially the minute hand since it doesn't have white lume running down the length of the hand. If I wasn't in my 50's that probably wouldn't be an issue.

But if the 2511 has the same size dial as the AT, I could buy one like the one below (2511.83), and swap the dial and hands into my AT. I love the AT case shape and size, but the hands are killing me right now.

As an alternative, I could source some 1.20/0.70 hands with better lume (for a greater contrast against the blue dial) and have them installed on my AT. I'm searching now.

That's actually a fairly cool looking Omega reference, I don't think I've ever seen it. some Blancpain / jlc vibe almost

502 to right · Mar 11, 2026

ErichPryde
That's actually a fairly cool looking Omega reference, I don't think I've ever seen it. some Blancpain / jlc vibe almost

Apparently it was only available in Japan. It has a bit of an Explorer and Railmaster vibe, but with a date. It also can be paired with a Peter Blake/Speedy type bracelet.

ErichPryde · Mar 11, 2026

502 to right
Apparently it was only available in Japan. It has a bit of an Explorer and Railmaster vibe, but with a date. It also can be paired with a Peter Blake/Speedy type bracelet.

Yeah, it's really cool. The hands are sorta reminiscent of some blancpain models, and the numerals are Explorer/Railmaster/JLC-esque. Throw in a bit of aquaterra and the classic lyre lugs... I often see some of these references as lacking clear design language but I like this one!