Omega Seamaster Planet Ocean Ultra Deep Review by Tim Mosso

by Tim Mosso

Watch writers aren’t known for deep thoughts. When we’re not jetting to expense-paid press junkets fueled by champagne and caviar, we tend to choose our words carefully lest we lose our golden ticket to the next tropical resort orgy of pricey booze and fish eggs.

But I’m an aftermarket outlaw among the polite company of watch writers, so I can get away with almost anything. Take my word when I assure you that Omega’s ultimate dive watch is both ridiculously deep-diving and… well… ridiculous.

Thanks to the Seamaster Planet Ocean Ultra Deep, Omega has put – extremely – deep thoughts back on the menu.

Omega Seamaster Planet Ocean Ultra Deep

While the Ultra Deep’s 18.1mm thickness seems to beggar belief, Omega wants you to understand that this is the mid-size version.

Omega Seamaster Planet Ocean Ultra Deep

A 28mm thick 2019 prototype, which may yet spawn a production model to battle Rolex’s Deepsea Challenge, provided the inspiration for the present flagship of the Planet Ocean collection.

Similar appearance and nomenclature aside, there are technical distinctions like the difference in dimensions and diving depth; the 2019 watch was rated to 15,000 meters.

Omega Seamaster Planet Ocean Ultra Deep

At 45.5mm and 51.5mm lug-to-lug, the series production Ultra Deep is a brick of metal suitable for descents to 6,000 meters and potential off-label dosing as a brass knuckle.



Since its 2022 debut, the POUD has discommoded the PloProf as Omega’s ultimate diving instrument. While the 1,200-meter PloProf remains unrivaled for weirdness, the Ultra Deep reclaims the flagship status originally held by the Planet Ocean series upon its 2005 debut.

The example featured in today’s study is a steel model on a rubber strap, but it’s only one among several color, bracelet, and metal configurations available.

For those who seriously plan to dive and stay alive, an electronic dive computer is mandatory, but the titanium variant of the Ultra Deep is the most logical choice for a backup timer.

Omega Seamaster Planet Ocean Ultra Deep

Its lighter construction, mandatory looped “manta” lugs, and the factory NATO strap serve the remaining “actual diver” marketplace that hasn’t already selected a Seiko for value or a Rolex for status.

A full steel bracelet is the only bracelet offered. It only mates to steel cases and packs both a 2.3mm micro-adjuster and a fold-out dive suit extension in its clasp.

With a view to value and convenience, the featured rubber/steel tandem is the most logical way to spec an Ultra Deep. And it wore comfortably – if comically – on the author’s 16cm baby wrist. But, as with lifted dually diesel one-ton pickup trucks, there’s plenty of bravado in this bomber Omega to compensate for anatomical shortcomings.

So long as your pencil-thin biceps can cash the physical checks written by your ego, the Ultra Deep will give any mid-level associate ultimate bragging rights in a Rolex-intensive office park.



With its POUD, Omega launched a new salvo in the Steel Wars that has ravaged collector bank accounts and driven countless refugees from the decimated wastes of 316L alloy. Rolex gave us 904L – pardon, “Oystersteel” – and ignited a world war against Ice Hardened steel, carburized steel, and Tegiment steel.

The former Axis powers retaliated with Panerai eSteel, Seiko DiaShield, and a flotilla of Sinn U-Boat Stahl amid a general mobilization of marketing departments. All advert copywriters of legal age have been drafted into the conflict.

Omega hits the battlefield armed with O-Megasteel. Pardon me… Omega wants you to know the written convention is O-MEGASTEEL. Hublot’s press office would be impressed.

At first glance, O-MEGASTEEL looks like it might be a more corrosion-resistant alloy using Rolex-style 904L; brands as disparate as Girard-Perragaux and Garrick have also used this material. But Omega advises that this is nickel-free steel, which rules out 904L. It may offer a benefit for those with extreme nickel allergies.

Omega Seamaster Planet Ocean Ultra Deep

More intriguing to the greater collecting collective is Omega’s claim of 40-50 percent greater scratch resistance. Omega’s marketing department dubiously insists its ferrous blend is brighter and whiter than rival steel, but this proved impossible to verify even with the watch in hand.



The shape of the Ultra Deep is recognizably that of a Planet Ocean, but the case, bezel, caseback, crown, crystal, and dial all are unique to this series. In detail, the lugs are shapely and converge with greater terminal taper than a standard PO.

The crown guards have a bit of a vintage air with their squared off profiles, and the crown itself is a massive affair that’s polished, media blasted, and deeply threaded into the caseband.

Back of the Omega Seamaster Planet Ocean Ultra Deep

Even the steel models have a titanium core at the center of the screwed-in caseback, and it bears the sea horse or “hippocampus” emblem that has graced Seamasters since time immemorial.

Omega dive bezels long have been the Lincoln Navigator to Rolex’s Cadillac Escalade, but the Ultra Deep evens the score. For the first time in my experience with hundreds of Seamasters, I’ve encountered an example whose indexing felt like the qualitative equivalent of what one feels when setting the bezel of a Submariner.

Omega Seamaster Planet Ocean Ultra Deep

The 120-click action isn’t gritty or coarse like other Seamaster Professional series that I’ve tested.

Not only is the click crisp, but the bezel glides smoothly between detents. The relative crudity of the old-school SMP bezel has been banished to the dungeon where Omega keeps the infamous A-series 2500 calibers and the condemned 1954 Synchrobeat.



Topside, the Ultra Deep packs plenty of the Planet Ocean’s long-running orange accents. We’re only a decade removed from Omega’s absurd $75,000 platinum Planet Ocean GMT “orange ceramic” eight-piece edition that debuted this technology.

Omega Seamaster Planet Ocean Ultra Deep lume hot

On that basis, the Ultra Deep’s orange ceramic cap – formerly orange rubber – still feels special. This bezel packs plenty of lume, and it glows blue throughout its 360 degrees of calibrated sectors.

For good measure, the bezel pearl and the minute hand glow green to permit easier reading of the two cardinal reference points in the dark.

Omega Seamaster Planet Ocean Ultra Deep

Dial design of the Ultra Deep offers both more and less than a standard Planet Ocean. There’s “more” in the sense that it shelters under 5.2mm of double-AR-coated sapphire crystal.

Another PO-series addition is the lacquer-fade treatment; it feels predictable in 2023 but remains handsome on its own terms. “Less” comes in the form of a no-date dial.

Omega Seamaster Planet Ocean Ultra Deep

Legions of dive watch purists will celebrate the culling of a visual wart beloved of the mass-market, but few in the rooting section are likely to write a check for this monster.

Ultimately, the absence of a calendar is another strike on a long list of reasons the Ultra Deep will never be a mass-market watch.

Omega Caliber 8912

Mechanically, the Ultra Deep isn’t novel in any regard. The Omega caliber 8912 parallels the 8900 in a 600-meter Planet Ocean, but the 8912 lacks a date. An automatic winding system energizes the 60-hour power reserve; this felt ahead of the industry when the caliber 8500 architecture launched in 2007, but it’s 10 hours fewer than comparably priced watches as of late 2023.

Omega offers a mobile hour hand that can be helpful to travelers, and a combination of components headlined by a silicon hairspring are responsible for the nearly non-magnetic qualities of the watch.



The caliber’s most interesting element remains the tri-level Co-Axial escapement. It’s a double-impulse escapement with direct and indirect action against the impulsed surface, but the longtime distinction between tangential friction (Co-Axial) and sliding (Swiss lever) is the controlling idea.

Tangential is what George Daniels billed as the core virtue of his concept, and it’s said to be less than the sliding variety. It is a challenge to unwind all the factors that contribute to the precise running of a movement, but I can confirm that I’ve tested each successive version of the Omega 8500/8900 series running to a second or less gained per day through the five standard test positions.

Master Chronometer (METAS) certification is part of the package. As a six-position test of the fully assembled watch, the Master Chronometer test evaluates the timepiece to and beyond the ISO 3159 that underpins the COSC’s five-position bare movement test. Winding efficiency, power reserve, durability, water resistance, and magnetic resistance are included in the test battery.

The METAS standards are laudable, but with Tudor’s recent arrival, they no longer count as an Omega exclusive.

While there’s no doubt the 8500/8900 series movements can far surpass any mass-market chronometry standard, the same is true of relatively conventional Swiss lever systems from other leading brands or Rolex’s LIGA-fabricated Chronergy lever escapement.



In short, Omega has chosen one of many paths to excellent timekeeping, albeit one that comes with a cooler Daniels-powered back story than most. And no, you shouldn’t take this to your local “guy” for anything other than a water test.

Omega Seamaster Planet Ocean Ultra Deep

For that matter, your local guy probably shouldn’t be opening the novel 6,000-meter case, either. All versions of the Ultra Deep are advertised as viable for saturation diving, but no helium release valve is provided.

Omega’s premise is the same as on the original Seamaster 600 “PloProf” of the 70s; the case is hermetically sealed to such a degree as to be impregnable to helium gas. Therefore, no gas gets in so none needs to “escape” by a valve.

Moreover, the caseback of the Ultra Deep includes a permanent vertical orientation and – regardless of case material – a separate center disc of titanium.

Lethal-depth dive watches are a curious class of consumer product. Diving to roughly 20,000 feet is beyond every human’s endurance, every diving suit’s limit, and the crush depth of all full-size submarines.

By comparison, 350+ kilometer-per-hour hypercars, recreational space flight, and Moto GP race replica bikes can, in theory, be enjoyed without entailing the deaths of their owners.

Omega Seamaster Planet Ocean Ultra Deep

But unlike any of those fringe luxuries, the 6,000-meter Seamaster Planet Ocean Ultra Deep can, with patient savings, be bought by a regular person. For those not named Branson, Musk, or Bezos, the Ultra Deep offers the braggadocio of outrageous excess at used car prices.

For more information, please visit

Quick Facts: Omega Seamaster Planet Ocean Ultra Deep
Functions: Hours, minutes, seconds, independent hour hand, 600-meters
Case: Stainless steel (as shown), 45.5mm x 18.1mm x 51.9mm: 22mm lug spacing, unidirectional 120-click ceramic-capped diving bezel
Water resistance: 6,000 meters/20,000 feet
Dial: Gradient grey with lacquer fade, quarter Arabic numerals
Movement: Caliber 8912, automatic, 60-hour power reserve, METAS chronometer, silicon hairspring, independent mobile hour hand, hacking seconds, two mainspring barrels
Price (2023): $12,300

* Tim Mosso is the media director and watch specialist at Watchbox. You can check out his very comprehensive YouTube channel at

You might also enjoy:

Why a Dive Watch should Never Be Haute Horlogerie

A Comprehensive Look At Mechanical Depth Gauge Watches

The Diving Bezel: The Most Versatile Watch ‘Complication,’ Even If You’re Not A Diver

Blancpain Fifty Fathoms: Story Of The World’s First Diving Watch (Video)

Omega vs. Rolex: How Omega is Reaching for the Crown

4 replies
  1. Mateen shahab
    Mateen shahab says:

    Hello again, I am using the Amiga watch, it is the best and the best quality watch, even if the watch is in my hand, I don’t feel tired, it is really great.

  2. Brian
    Brian says:

    Beautifully written and authoritative. Watches like the Ultra Deep are functional fetish items worthy of both praise and scorn. I have a bargain-basement Seapro Abyss that approximates the style and excess of the UD at a price that encourages one to wear the thing for something other than cocktail parties.

  3. Russell Brackin
    Russell Brackin says:

    So, a long time ago i bought a TAG formula 1 when they were first issued, my friends at work called it a plastic watch, a 200m diving watch, I could just about swim this far but on a night out it was bomb proof perfect value for money. Built for collectors, divers don’t go this deep on a regular basis, made for people who deserve to drown, those with a lot of cash that snorkel in the Maldives or briefly dive for the Titanic. Perspective pretty watch s an engineering art piece.


Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *