Equipped with one of the world’s most advanced mechanical movement, the Seamaster Aqua Terra Master Co-Axial is stylish, sporty and prepared for an active lifestyle. This luxurious model features a pearled mother-of-pearl dial with 11 diamond indexes in 18K gold holders.
This 38.5 mm 18K red gold ladies' wristwatch, with its diamond-set bezel, is presented on an 18K red gold bracelet. At its heart is the revolutionary OMEGA Master Co-Axial calibre 8501, a movement that can resist strong magnetic fields - even those greater than 15,000 gauss.
Anti-magnetic
The movement is unaffected by exposure to strong magnetic fields, even those greater than 1.5 tesla (15,000 gauss).
Chronometer
Label given to a watch which has undergone precision tests and received a certificate from an official body (COSC).
Date
The day of the month, displayed in a window on a watch dial at the 3 or 6 o’clock position, or within a subdial at 9 o'clock.
Diamonds
The hardest, most luminous precious stone whose value is calculated according to the 4C criteria: Cut - Carat - Clarity - Color.
Screw-in crown
Self-locking crown, screwed into the tube of the case, used for highly water resistant divers' watches.
Time zone function
Allows the hour hand to be easily adjusted to different time zones without stopping the watch.
Transparent caseback
A transparent caseback - frequently made of sapphire - makes it possible to see the movement inside the watch.
Reference
231.55.39.21.55.001
Between lugs
Open Case Measurement Modal
19 mm
Lug‑to‑lug
Open Case Measurement Modal
45.5 mm
Thickness
Open Case Measurement Modal
12.8 mm
Case diameter
Open Case Measurement Modal
38.5 mm
Case
Red gold
Dial colour
White
Crystal
Domed scratch‑resistant sapphire crystal with anti‑reflective treatment on both sides
Water resistance
15 bar (150 metres / 500 feet)
Watch size
Ladies
Total product weight (approx.)
206 g
Calibre
Omega 8501
Movement Type
Self winding
Power reserve
60 hours
Case Measurements
1. Between lugs
This measures the space where a strap or bracelet would be placed.
2. Lug-to-lug
This is the full length of the case, from the top lugs to the bottom lugs.
3. Case diameter
This is the full width of the watch’s case, excluding the crown and pushers.
4. Thickness
When viewed from the side, this measures from the base of the watch to the surface of the glass.
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Key materials
Red Gold
Diamonds
Mother-of-pearl
Sapphire Crystal
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Red Gold
Gold in its pure form (24K) is slightly reddish yellow and very soft. It is usually alloyed with other base metals for a diverse variety of uses. Considered to be the premium standard in watch and jewellery making, 18K golds (with at least 75% pure gold) provides the ultimate balance between purity and usefulness. Traditional 18K red gold is alloyed with copper-silver and offers an excellent resistance to corrosion, while being highly bio-chemically inert. It provides a beautiful hue that suits wearers even with sensitive skin.
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Diamonds
Diamond is recognised as the hardest material on Earth, graded 10 on the Mohs hardness scale, and is the only gem made entirely of carbon. In nature, it can only be formed under high temperature and pressure conditions that exist within a specific depth range (~100 miles) beneath the Earth's surface. To decorate its timepieces and jewellery, OMEGA uses "Top Wesselton" white COLOUR diamonds with CLARITY ranging from pure to VVS (Very Very Small inclusions). Along with choosing the best weight in CARAT, the CUT is also carefully selected in order to maximise brightness and scintillation. It goes without saying that OMEGA is a certified member of the non-profit Responsible Jewellery Council (RJC), assuring customers that its processes involving people, materials and the environment are ethical and fair.
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Mother-of-pearl
Also known as "nacre", mother-of-pearl is an organic-inorganic composite material produced by some molluscs as an inner shell layer, similar to pearls. It is strong, resilient and iridescent, with changing colours depending on the wavelengths of light at different viewing angles. Produced with exquisite skill and delicacy, OMEGA's ladies' collection offers mother-of-pearl dials of top quality, enhanced with specific attributes.
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Sapphire Crystal
To really appreciate the finer details of a timepiece, OMEGA uses synthetic sapphire crystal with a highly scratch-resistant and anti-reflective treatment. Before the machining and finishing processes take place, the sapphire crystals are produced under the Verneuil process, also called flame fusion. It involves the melting of the raw substance using oxyhydrogen flame and the crystallisation of the melted droplets to form a cylinder. Graded 9 on the Mohs-hardness scale (graded 1-10), the resulting sapphire crystals are virtually scratch-proof and very hard, ensuring an unhindered vision at all times.
Gold in its pure form (24K) is slightly reddish yellow and very soft. It is usually alloyed with other base metals for a diverse variety of uses. Considered to be the premium standard in watch and jewellery making, 18K golds (with at least 75% pure gold) provides the ultimate balance between purity and usefulness. Traditional 18K red gold is alloyed with copper-silver and offers an excellent resistance to corrosion, while being highly bio-chemically inert. It provides a beautiful hue that suits wearers even with sensitive skin.
Diamonds
Diamond is recognised as the hardest material on Earth, graded 10 on the Mohs hardness scale, and is the only gem made entirely of carbon. In nature, it can only be formed under high temperature and pressure conditions that exist within a specific depth range (~100 miles) beneath the Earth's surface. To decorate its timepieces and jewellery, OMEGA uses "Top Wesselton" white COLOUR diamonds with CLARITY ranging from pure to VVS (Very Very Small inclusions). Along with choosing the best weight in CARAT, the CUT is also carefully selected in order to maximise brightness and scintillation. It goes without saying that OMEGA is a certified member of the non-profit Responsible Jewellery Council (RJC), assuring customers that its processes involving people, materials and the environment are ethical and fair.
Mother-of-pearl
Also known as "nacre", mother-of-pearl is an organic-inorganic composite material produced by some molluscs as an inner shell layer, similar to pearls. It is strong, resilient and iridescent, with changing colours depending on the wavelengths of light at different viewing angles. Produced with exquisite skill and delicacy, OMEGA's ladies' collection offers mother-of-pearl dials of top quality, enhanced with specific attributes.
Sapphire Crystal
To really appreciate the finer details of a timepiece, OMEGA uses synthetic sapphire crystal with a highly scratch-resistant and anti-reflective treatment. Before the machining and finishing processes take place, the sapphire crystals are produced under the Verneuil process, also called flame fusion. It involves the melting of the raw substance using oxyhydrogen flame and the crystallisation of the melted droplets to form a cylinder. Graded 9 on the Mohs-hardness scale (graded 1-10), the resulting sapphire crystals are virtually scratch-proof and very hard, ensuring an unhindered vision at all times.
A new look for your watch
Your watch and strap should go together perfectly, but that doesn't mean you can't experiment with different combinations. Why not mix things up and see what happens? You may discover a look that's as individual as you are.
Find your perfect Strap
Configure your Strap
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The advantages of this watch
The advantages of this watch
A key component of this timepiece is the Co-Axial escapement, which is able to maintain accuracy over a longer period of time. What’s more, all parts affecting accuracy are produced with non-ferromagnetic materials, ensuring the watch is protected from the strong magnetic fields produced by everyday items.
Superior Precision
Our Master Co-Axial Chronometer movements benefit from the Co-Axial escapement, which is able to maintain accuracy over a longer period of time. All parts affecting accuracy are also produced with non-ferromagnetic materials, ensuring that that precision will not be affected by magnetism (up to 15'000 gauss). Each movement is Chronometer-certified according to international standard ISO3159, requiring a precision of -4/+6 second per day, following the tests at the Official Swiss Chronometer Control (COSC).
Anti-magnetic
Proprietary anti-magnetic materials
Everyday items such as mobile phones, metal clasps on handbags, laptops, MRI, induction hobs or automatic doors; subject a watch to magnetic fields and can affect its performance. To prevent the risk of permanent deviations of up to several minutes a day we've conceived movements with antimagnetic materials, such as the silicon balance spring, capable of withstanding the highest fields.
Water-Resistance
To ensure the integrity of our timepieces at depth, not just some but all watches are fully immersed in water and pressure is applied up to the point of the guaranteed water resistance. By submerging each watch in water we have chosen – yet again - to exceed normal testing standards.
5-Year Warranty
In our quest to raise industry standards and push the boundaries of quality, all OMEGA watches are offered with a full 5-year warranty. This customer promise shows the confidence we have in the excellence of our timepieces, and provides extra trust and assurance when choosing your watch.
Less Servicing
Expect fewer visits to the service centre. The Co-Axial escapement is designed to reduce friction inside the movement. As a result, less lubrication is needed and hence less servicing. Compared to non-Co-Axial watches, the intervals between getting your watch serviced will be much longer.
Shock-resistance
During the homologation process, OMEGA watches are tested to the extreme. This phase includes shock examinations, to confirm reliability and to check that its precision is maintained after a severe impact. All OMEGA timepieces are designed to withstand shocks corresponding to a 1-metre drop on a hard wooden floor. For a standard 150g timepiece, this sudden and rapid acceleration is an equivalent force of up to 5,000 G on the watch head.
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Superior Precision
Our Master Co-Axial Chronometer movements benefit from the Co-Axial escapement, which is able to maintain accuracy over a longer period of time. All parts affecting accuracy are also produced with non-ferromagnetic materials, ensuring that that precision will not be affected by magnetism (up to 15'000 gauss). Each movement is Chronometer-certified according to international standard ISO3159, requiring a precision of -4/+6 second per day, following the tests at the Official Swiss Chronometer Control (COSC).
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Anti-magnetic
Proprietary anti-magnetic materials
Everyday items such as mobile phones, metal clasps on handbags, laptops, MRI, induction hobs or automatic doors; subject a watch to magnetic fields and can affect its performance. To prevent the risk of permanent deviations of up to several minutes a day we've conceived movements with antimagnetic materials, such as the silicon balance spring, capable of withstanding the highest fields.
3 / 6
Water-Resistance
To ensure the integrity of our timepieces at depth, not just some but all watches are fully immersed in water and pressure is applied up to the point of the guaranteed water resistance. By submerging each watch in water we have chosen – yet again - to exceed normal testing standards.
4 / 6
5-Year Warranty
In our quest to raise industry standards and push the boundaries of quality, all OMEGA watches are offered with a full 5-year warranty. This customer promise shows the confidence we have in the excellence of our timepieces, and provides extra trust and assurance when choosing your watch.
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Less Servicing
Expect fewer visits to the service centre. The Co-Axial escapement is designed to reduce friction inside the movement. As a result, less lubrication is needed and hence less servicing. Compared to non-Co-Axial watches, the intervals between getting your watch serviced will be much longer.
6 / 6
Shock-resistance
During the homologation process, OMEGA watches are tested to the extreme. This phase includes shock examinations, to confirm reliability and to check that its precision is maintained after a severe impact. All OMEGA timepieces are designed to withstand shocks corresponding to a 1-metre drop on a hard wooden floor. For a standard 150g timepiece, this sudden and rapid acceleration is an equivalent force of up to 5,000 G on the watch head.
MovementCalibreOMEGA 8501
Self-winding movement with Co-Axial escapement. Free sprung-balance, 2 barrels mounted in series, automatic winding in both directions. Oscillating mass and balance bridge in red gold. Luxury finish with exclusive Geneva waves in arabesque.
