Omega Seamaster Aqua Terra 231.15.39.21.51.001

Omega Seamaster Aqua Terra 231.15.39.21.51.001 is a pre-owned watch, inspected by our certified watchmaker in Geneva and offered by WATCHOYSTER. It ships worldwide, fully insured. The photos show the actual watch, and the sections below cover what matters when you choose between examples of this reference.

Design and case

Black dials are where originality matters most on a pre-owned watch, so check the photos for even colour, crisp printing and lume that has aged at the same rate as the hands. The numeral style, "Lines", sets how formal the dial looks and how quickly the time can be read at a glance. Sapphire crystal sits over the dial, and the type shapes how the watch ages: sapphire resists scratches best, mineral glass is cheaper to replace, and acrylic can usually be polished back. Gem-set bezels take the first knocks on any watch, so look for dents, chips and rubbing along the edge, and on a rotating bezel check that it turns cleanly and the insert has not faded.

Steel cases differ in weight and in how they carry scratches and polishing marks, so compare the case photos with the condition grade below. At 38.5 mm, judge the case against your own wrist, because the same size can look quite different depending on lug length. A case thickness of 13.5 mm decides whether the watch slides under a shirt cuff or stands proud of it. 19 mm between the lugs is the measurement to have at hand if you plan to fit a different strap.

Steel cases show their history in two places: the surface and the edges. Rounded lugs and blurred bevels suggest the case has been polished more than once, so compare the case photos with the condition grade below. At 38.5 mm, the figure that decides how the watch sits is the lug-to-lug distance rather than the diameter alone, so compare it with a watch you already wear or ask us for the measurement. A case thickness of 13.5 mm decides whether the watch slides under a shirt cuff or stands proud of it, and it changes how the watch sits on a smaller wrist. 19 mm between the lugs is the measurement for a replacement strap, and it is worth checking before you buy one, because watches with integrated bracelets often take only the maker's own straps.

Steel wears in its own way: metal bracelets stretch and open small gaps between links, while straps show age at the holes and edges, so read the photos of the strap or bracelet with that in mind. A strap or bracelet in "Steel" does as much as the dial colour to set the character of the watch, and it is the easiest part to change later. The closure is listed as "Double-fold clasp", and it is one of the first parts of a bracelet to show wear, so it deserves a close look in the photos.

Steel clasps should match the bracelet in finish, so compare the two in the photos: a clasp that looks clearly newer than the links can point to a replaced part. It belongs to the Seamaster line, so comparing it with other examples from the same family is the quickest way to judge whether the price is fair. The watch is filed under "Women's watch", which indicates intended size and styling more than who may wear it.

Movement and technical details

Automatic movements ask for different upkeep: mechanical ones typically need a service every five to ten years, while quartz ones need a battery change and an occasional gasket check.

With 60 h of power reserve, the watch runs for that long once fully wound, which matters most if you rotate between several watches.

A frequency of 25200 A/h defines how finely the movement divides each second: higher beat rates give a smoother sweep of the seconds hand, while lower ones tend to extend the power reserve. The movement uses 39 jewels, synthetic rubies that serve as low-friction bearings at the pivots; the number says more about how the movement is built than about its quality.

Water resistance is stated as "15 ATM"; the figure applies to new seals, so on a pre-owned watch we advise a pressure test before it goes near water, and a 30 m rating means splash resistance only. It dates from 2023, and the year matters because dials, hands, lume and bracelets often changed within a single reference.

Condition and set

Any wear is visible in the photos, and we describe it as plainly as we can. Used (Very good) is the grade we assign after inspecting the case, dial, bezel, crystal, and bracelet, and the photos show the wear behind that grade. The set is described as "Original papers, no original box". Box and papers document provenance, and a watch with a full set is usually easier to resell.

The reference number 231.15.39.21.51.001 separates this version from other variants of the model, down to dial, bezel and bracelet details, so match it against the photos before you buy.

Authenticity and service

Every watch sold by WATCHOYSTER is inspected and authenticated by our certified watchmaker and verified against The Watch Register before it reaches you. Each piece comes with our warranty and a 14-day return policy. Interested in the Omega Seamaster Aqua Terra 231.15.39.21.51.001? Write to us on WhatsApp, and we will send additional photos and delivery details.