Omega Seamaster Diver 300M Co-Axial Master Chronometer 42 mm 210.30.42.20.01.001

The Seamaster Diver 300M Co-Axial Master Chronometer 42 mm, ref 210.30.42.20.01.001, is the all-steel, black-dial configuration of Omega's dive line as relaunched in 2018 for the model's 25th anniversary. It pairs a 42 mm stainless steel case rated to 300 m with a polished black ceramic wave dial and a matching black ceramic diving bezel, and runs the METAS-certified Co-Axial Master Chronometer Calibre 8800, visible through a sapphire caseback. This reference ships on a stainless steel bracelet.

The Seamaster Professional Diver 300M was introduced in 1993 with a choice of quartz or automatic movements, and reached a broad audience after Pierce Brosnan wore a quartz version as James Bond in GoldenEye (1995). Its laser-engraved "wave" dial pattern, per Prestige Time, was a feature of the line from 1993 to 2011.

Later generations adopted Omega's Co-Axial calibre 2500 and a ceramic bezel but dropped the wave dial, according to Monochrome's hands-on coverage. That set the stage for a full revision.

In 2018, for the model's 25th anniversary, Omega overhauled the line: it restored the wave motif — now laser-engraved into a ceramic dial — enlarged the case from 41 mm to 42 mm to fit the new movement, moved the date from 3 o'clock to 6 o'clock, fitted a sapphire caseback in place of the solid one, and upgraded to the Master Chronometer calibre 8800. Fourteen new references debuted at Baselworld 2018. Ref 210.30.42.20.01.001 is the all-steel, black-dial member of that generation.

The watch runs Omega's Calibre 8800, an automatic movement with the Co-Axial escapement, certified as a Master Chronometer by METAS. Monochrome lists a 55-hour power reserve and a 25,200 vph (3.5 Hz) beat rate.

Its defining trait is magnetic resistance. A silicon balance spring and non-ferrous components allow the movement to withstand fields to 15,000 gauss, a figure Omega had verified under the METAS protocol. In its review, Monochrome describes a free-sprung balance and finishing that includes rhodium-plated bridges with Geneva waves plus blackened barrel, balance and screws, all on view through the sapphire caseback.

The 8800 replaced the earlier Co-Axial calibre 2500 used in previous 300M generations; per Prestige Time and Monochrome, the move to a 42 mm case was made in part to accommodate the newer movement.

Published measurements put the 42 mm steel case at roughly 50 mm lug-to-lug with a 20 mm lug width, per Monochrome. In its hands-on of the 42 mm ceramic Diver 300M, the Monochrome reviewer described the sizing as fitting "squarely in the 'just right' category," but found the smooth ceramic bezel "a little harder to grip and rotate than I would like."

Teddy Baldassarre, wearing the ceramic Diver 300M — which shares its case and bezel with the black-dial reference — took the opposite view of the bezel, calling the action "very good" and saying the common grip complaint never affected him. He singled out the case finishing, describing the twisted lyre lugs with alternating brushed and polished surfaces as showing "a level of refinement and thoughtfulness in finishing that you don't often see in dive or tool watches."

Baldassarre found the watch "highly legible" despite the skeletonized hands, said it "wears a little bit bigger" than its 42 mm nominal size yet felt "a little thinner on the wrist" than its roughly 13.6 mm height suggests, and noted that the substantial steel bracelet adds noticeable weight.

The 2018 relaunch spanned fourteen references. In steel, the black-dial version is offered on either a stainless steel bracelet — this reference, 210.30.42.20.01.001 — or a black rubber strap, sold as 210.32.42.20.01.001, per Watchmaxx and Exquisite Timepieces; Monochrome and Watch Collecting Lifestyle note that the same bracelet-or-strap choice runs across the collection.

Beyond black, Teddy Baldassarre's overview lists blue and green ceramic dials, a white-ceramic "Great White," and two-tone steel-and-Sedna-gold and solid-gold executions. Cases are produced in 42 mm and a larger 43.5 mm size, the latter with a 21 mm lug width rather than 20 mm.

All versions share the Master Chronometer platform, with the standard date models using calibre 8800. Across the wider line, Teddy cites retail spanning roughly $6,300 for entry steel models up to about $35,000 for precious-metal pieces.

At the 2018 launch, the steel Diver 300M on a rubber strap carried a US sticker price of $4,750, with the two-tone steel-and-gold rubber-strap model at $6,150, according to Watch Collecting Lifestyle's Baselworld pricing coverage. The bracelet version — this reference — is priced above the rubber model.

For current retail, US authorized dealer Exquisite Timepieces lists ref 210.30.42.20.01.001 (black dial, steel bracelet) at $6,700, sold with Omega's five-year warranty. Across the wider Diver 300M range, Teddy Baldassarre cites retail from roughly $6,300 for entry steel models up to about $35,000 for precious-metal versions.

The watch is distributed through Omega boutiques and authorized dealers. The black-dial steel model is the most common configuration and is sold alongside a rubber-strap sibling and blue, green and two-tone options, so a buyer's main choices are dial color and whether to take the steel bracelet or rubber strap.