The Omega Seamaster Aqua Terra Ultimate Guide


The Omega Seamaster Aqua Terra Ultimate Guide

The Omega Seamaster Aqua Terra (AT) is a fantastic watch that is very versatile and is a strong candidate for your one watch collection. This watch is the perfect mix between a sport and a dress watch. It will look good on you no matter what you wear.

The Omega Seamaster Aqua Terra (AT) is a fantastic watch that is very versatile and is a strong candidate for your one watch collection. This watch is the perfect mix between a sport and a dress watch. It will look good on you no matter what you wear.

If we had to compare this to a Rolex model, we would say it's a mix between a DateJust and an Explorer. This is therefore in our opinion a great alternative to those Rolex models.

First released in 2003 and last updated in 2017, this watch has changed a lot over the years. The older models have a more classic and timeless design, whereas new ones are more sporty and modern-looking. You will find below all the different Omega Seamaster Aqua Terra models and their details.

First released in 2003 and last updated in 2017, this watch has changed a lot over the years. The older models have a more classic and timeless design, whereas new ones are more sporty and modern-looking. You will find below all the different Omega Seamaster Aqua Terra models and their details.

Omega Seamaster Aqua Terra (250X.XX series)

The Omega Seamaster Aqua Terra (AT) is a fantastic watch that is very versatile and is a strong candidate for your one watch collection. It was released in 2003, sporting the first co-axial movement developed by Omega: the Omega 2500.

This first AT model got discontinued in 2010, it was available in 3 sizes:

  • 42.0mm (2502.XX)
  • 39.5mm (2503.XX)
  • 36.0mm (2504.XX)
  • Ref: 2504.30, 2504.50, 2504.70, 2504.80
  • Diameter: 36.00 mm
  • Thickness: 11.00 mm
  • Lug width: 19.00 mm
  • Caliber: Omega 2500

Some Omega Seamaster Aqua Terra models. Left: 2504.80, Center-top: 2504.30, Center-bottom: 2503.50. Available on eBay.
Some Omega Seamaster Aqua Terra models. Left: 2504.80, Center-top: 2504.30, Center-bottom: 2503.50. Available on eBay.

The lugs on those models are quite long, so the watch wears bigger than its diameter suggests. We find that the 36mm model in black (2504.50) is a great Rolex Explorer alternative.

The dial colors available for this timepiece are:

  • Black (250X.50)
  • Blue sunburst (250X.80)
  • Silver sunburst (250X.30)
  • Mother of pearl with blue markers and hands (250X.33)
  • Silver with gold markers and hands (250X.34)
  • Red (250X.60)
  • Ref: 2503.30, 2503.50, 2503.70, 2503.80
  • Diameter: 39.50 mm
  • Thickness: 11.50 mm
  • Lug width: 20.00 mm
  • Caliber: Omega 2500

The different sizes of the first generation Omega Seamaster Aqua Terra (36mm, 39.5mm, 42mm). The length of the 3 o'clock marker depends on the diameter.
The different sizes of the first generation Omega Seamaster Aqua Terra (36mm, 39.5mm, 42mm). The length of the 3 o'clock marker depends on the diameter.

No matter what the size is, the layout of the dial is the same. You will find a date window at 3 o'clock, along with a shortened hour marker.
The size of this marker will vary depending on the size of the watch: it is a good way to check out what the diameter is when you are looking at the pictures.

As mentioned earlier, the first AT models sport the Omega 2500 co-axial movement, which was first based on an ETA 2892 (before 2003) and Frederique Piguet (after 2003) movement to which a 2 level co-axial escapement was added. This movement is relatively thin, allowing the first AT models to be worn comfortably with a thickness of 11mm.

  • Ref: 2502.30, 2502.50, 2502.70, 2502.80
  • Diameter: 42.20 mm
  • Thickness: 11.60 mm
  • Lug width: 20.00 mm
  • Caliber: Omega 2500

Omega Seamaster Aqua terra 2503.XX case back
Omega Seamaster Aqua terra 2503.XX case back

Omega changed the 2500 caliber 4 times, through revisions A, B, C and D. The revisions A and B beat at 28,800vph whereas at C and D have an oscillation frequency of 25,200vph. The latter frequency is closer to what George Daniels envisaged in his co-axial movement.

The 2500D revision was released in 2011 and is therefore not equipping any Omega AT models since they were discontinued in 2010. The 2500D is however present in Omega Planet Ocean (PO) and DeVille models with serial numbers above 8525XXXX.

Here are 8 suggestions on eBay for the Omega Seamaster Aqua Terra (250X.XX series):
(scroll horizontally for more )

Omega Seamaster Aqua Terra (Skyfall series)

After the first Aqua Terra models were discontinued in 2010, a new model followed in the same year: the AT "Skyfall" - we call it Skyfall because it was worn by Daniel Craig in the Skyfall James Bond movie in 2012 (ref 231.10.39.21.03.001, blue model). Omega introduced a lot of changes in this model:

  • The dial featured a pattern made of vertical stripes
  • A date window frame was added
  • The shape of the hands was changed to make them look more sporty, their tip has been cut and they now expose a flat surface
  • A 60-minute graduation appeared on the outside of the hour markers
  • The shapes of the hour markers is very prominent and they are now covered with lume.
  • Finally an entirely new movement was built: the Omega 8500 co-axial movement.
Omega Aqua Terra 8500 vs 2500 face comparison
The AT 8500 (left) vs the AT 2500 (right), credits to Clarky's great post!
Omega Aqua Terra 8500 vs 2500 caseback comparison
Case backs of the AT 2500 and the AT 8500, by Clarky .

Unlike the 2500 which was based on an existing calibre (ETA 2892), the 8500 movement has been designed from scratch. It features a new co-axial escapement assembly with 3 levels as George Daniels designed it. Through the transparent case back, you can see 2 spring barrels that ensure precision even when power runs low. The power reserve of the Omega 8500 is 60 hours and the watch is COSC certified as you would expect.

This model was available in 2 sizes:

  • 38.5mm (ref 231.10.39.21.XX.XXX with 19mm lug width)
  • 41.5mm (ref 231.10.42.21.XX.XXX with 20mm lug width)

The thickness of the watch increased to 12.85mm with the 8500 movement, due to the 3 level co-axial escapement. As you can see from the pictures, there is a significant difference in height between the two models. The 2500 model is thin and discrete, whereas the 8500, with its bold and relatively chunky feel, has definitely more wrist presence.

The lugs of the Skyfall AT got shortened, making the 38.5mm model more adapted for smaller wrists than its 39.5mm diameter predecessor.

Omega Aqua Terra 8500 vs 2500 thickness comparison
The height between the AT 2500 and the AT 8500, credits to Clarky's great post!
Here are 8 suggestions on eBay for the Omega Seamaster Aqua Terra (Skyfall series):
(scroll horizontally for more )

Omega Seamaster Aqua Terra (Spectre series)

Following the Omega Seamaster Aqua Terra Skyfall model came the Aqua Terra Spectre model. As the name of the series suggests, it was worn during James Bond movie Spectre (2015) (ref 231.10.39.21.03.002 blue model).

There are subtle differences from the previous iteration:

  • The date frame disappeared
  • The movement started to incorporate anti-magnetic components - such as a silicon (Si14) balance spring - providing a resistance up to 15000 Gauss.

At that point, the movement revisions of the Omega 8500 movement had moved from A to B then directly to G - 8500G being the 15000 Gauss movement, there is no C version.

Omega Seamaster Aqua Terra Spectre blue dial
The Omega Seamaster Aqua Terra Spectre in Blue, credits to mesaboogie18's great post!
Omega Seamaster Aqua Terra Spectre blue steel bracelet
Omega Seamaster Aqua Terra Spectre with bracelet, by mesaboogie18.

Moreover, the bracelet now features a polished center link, all previous models had an entirely brushed bracelet until this model. This model was available in the same dimensions as the Skyfall ones: 38.5mm and 41.5mm and 13mm thick.

A few special editions models have been issued in that form factor, including the "Golf" edition (ref 231.12.42.21.01.003) and the James Bond "Spectre" edition (ref 231.10.42.21.03.004) limited to 15007 pieces.

Here are 8 suggestions on eBay for the Omega Seamaster Aqua Terra (Spectre series):
(scroll horizontally for more )

Omega Seamaster Aqua Terra 2017

Omega Seamaster Aqua terra 220.12.41.21.03.002
Omega Seamaster Aqua terra 220.12.41.21.03.002

In 2017 a new version of the Aqua Terra was released, providing with a new dial that features a horizontal pattern of grooves of varying width - the so-called teak pattern, supposedly inspired by the wooden decks of luxury sailboats.

The visual balance of the watch got improved with a symmetrical case design and a date window moved to the 6 o'clock position.

This new model is available on steel bracelet, leather strap and a very cool looking rubber strap.

Under the hood, a new movement will be found: the Omega calibre 8900 powers 41mm models whereas the calibre 8800 is in the 38mm diameter models.

Both movements are anti-magnetic up to 15000 Gauss, however some differences between those movements can be found:

  • The 8900 movement is higher and wider than the 8800.
  • The 8800 movement has a slightly smaller power reserve of 55hours compared to 60hours for the 8900.
  • The 8900 has a jumping hour hand, allowing you to very quickly change time zones without affecting the minute hands.

Moreover the 8800 and 8900 movements undergoes a certification process stricter than the COSC certification: the METAS certification, which is granted by the Swiss Federal Institute of Metrology.

The rubber strap of the Omega Seamaster Aqua terra 220.12.41.21.03.002
The rubber strap of the Omega Seamaster Aqua terra 220.12.41.21.03.002
Here are 8 suggestions on eBay for the Omega Seamaster Aqua Terra 2017:
(scroll horizontally for more )


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