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Illustrative render — hero view of the Omega Seamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet)

Omega · Seamaster Diver 300M · 42mm · steel and Sedna gold · on Amazon

The wave-dial Seamaster, in steel and Sedna gold.

This is the 2018 Seamaster Diver 300M that brought the waves back: a 42mm steel case, a Sedna gold bezel with a blue ceramic insert, a blue ceramic dial with laser-engraved waves, markers and skeleton hands edged in Sedna gold, the date at six, the helium valve at ten, on a steel bracelet with Sedna gold centre links. Inside is the calibre 8800, a Co-Axial Master Chronometer certified by METAS, with about 55 hours of reserve and 300 metres on the case. The two-tone version of the Seamaster Amazon shoppers search for most. Sold on Amazon by a marketplace seller shipping from Japan.

This Seamaster on Amazon$10,000–$25,000 band

Case

42mm, 13.6mm thick, steel, 18k Sedna gold unidirectional bezel with blue ceramic insert, helium escape valve, sapphire caseback, 300m

Listing title: 42mm, 300m; photograph; Omega 210.20.42.20.03.002 (the seller says 11mm thick; Omega says 13.6)

Movement

Omega Co-Axial Master Chronometer calibre 8800, METAS certified, about 55 h

Omega 210.20.42.20.03.002

Dial

Blue ceramic with laser-engraved waves, Sedna gold-edged luminous markers and skeleton hands, date at 6

Listing title: blue dial; photograph; Omega

Bracelet

Steel with 18k Sedna gold centre links, fold-over clasp with push-button release

Seller description; photograph

Reference

210.20.42.20.03.002

Listing title and model row

Seller

MS-TR JAPAN, marketplace seller shipping from Japan; in stock; 30-day returns; condition not stated

Amazon buy box, 2026-09-13

The 2018 Seamaster, and Sedna

Omega redesigned the Seamaster Diver 300M in 2018 for its 25th anniversary and gave it back the wave dial of the 1993 original, this time laser-engraved into ceramic so it will not fade. The bezel insert became ceramic too, and the movement became the 8800, a Master Chronometer tested by METAS for accuracy and resistance to 15,000 gauss. Sedna is Omega’s own rose gold alloy, mixed with copper and palladium so the colour holds, and on this reference it is on the bezel, the crown, the hands, the marker edges and the bracelet’s centre links.

The result is the Seamaster with the most colour on it: blue ceramic against rose gold against brushed steel. The helium escape valve at ten is the Seamaster signature; the date sits at six on this generation, not at three.

Illustrative render — the 2018 seamaster, and sedna of the Omega Seamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet)

Reading the listing

The listing carries the full reference, 210.20.42.20.03.002, in the title and the model row, and the seller’s description lists the blue dial, steel case, steel and 18k Sedna gold bracelet, automatic movement, 300 metres, unidirectional bezel, fold-over clasp with push-button release and a 42mm case. The one figure that disagrees with Omega is the thickness: the seller says 11mm, Omega publishes 13.6mm, and the copy here uses Omega’s. The calibre, its METAS certification, the reserve and the sapphire caseback are Omega’s published figures for the reference.

The seller is MS-TR JAPAN, a marketplace seller shipping from Japan, and the rows we read do not state whether the watch is new with Omega’s warranty; ask, and ask for the box and warranty card. Every figure here comes from the listing and from Omega’s published description, not from handling the watch.

Illustrative render — reading the listing of the Omega Seamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet)

Buying it on Amazon

This is a regular Amazon listing from a marketplace seller with Amazon’s 30-day return window; it is not a Luxury Stores pre-owned unit and the seller has not published a condition. The second button opens the live search for two-tone Seamaster Diver 300Ms in case this one has sold.

Seamaster Diver 300Ms have resold for under new and close to what pre-owned buyers paid, sometimes more, sometimes less; that is a pattern, not a promise, and nothing here is investment advice.

Illustrative render — buying it on amazon of the Omega Seamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet)

Specs

Reference
210.20.42.20.03.002
Case size
42mm, 11mm thick per the seller (Omega: 13.6mm)
Case material
Stainless steel with an 18k Sedna gold unidirectional bezel and blue ceramic insert, helium escape valve, sapphire caseback
Movement
Automatic, Omega Co-Axial Master Chronometer calibre 8800 (METAS)
Caliber type
Omega 8800, Master Chronometer
Crystal
Sapphire Crystal
Water resistance
300m (30 ATM)
Power reserve
About 55 hours
Complications
Date
Origin
Swiss Made

Specifications as published by Omega. We research from manufacturer documentation and published sources rather than hands-on testing. Researched 2026-09-13.

Verdict

The 2018 Seamaster Diver 300M in steel and Sedna gold with the blue wave dial, on Amazon from a Japanese marketplace seller: the two-tone version of the most searched-for Omega, with the METAS movement and the full reference on the listing.

Strengths

  • Calibre 8800 Master Chronometer, about 55 hours, 300 metres
  • Blue ceramic wave dial and ceramic bezel insert; neither fades
  • Sedna gold on the bezel, hands, markers and bracelet links
  • Full reference on the listing; Amazon’s return window

Trade-offs

  • Ships from Japan; condition and warranty not stated, ask
  • Two-tone is a look; the all-steel version is quieter
  • Seller’s thickness figure is wrong; expect 13.6mm
  • 42mm and a bracelet with gold links; heavier than steel

Buy it if

Someone who wants the modern Seamaster with rose gold on it and a movement certified beyond chronometer.

Skip it if

You want the all-steel Seamaster, a stated condition, or a lighter watch.

This Seamaster on Amazon$10,000–$25,000 band

FAQ

Omega’s own 18k rose gold alloy, with copper for the colour and palladium to keep it from fading. On this reference it is used for the bezel, crown, hands, marker edges and the bracelet’s centre links.

Compare

OmegaSeamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet) vs Seamaster Diver 300M 42mm (Sedna gold, rubber)OmegaSeamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet) vs Seamaster Diver 300M Co-Axial 41mm (steel, black dial, ceramic bezel, bracelet)RolexSeamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet) vs Submariner Date 16803 (steel and 18k yellow gold, black dial, black bezel)

Sources

Researched and last updated 2026-09-13. We do not test watches in hand; every figure above is traceable to the manufacturer or the sources listed here.

Omega Seamaster Diver 300M Co-Axial Master Chronometer 42mm 210.20.42.20.03.002 (steel and Sedna gold, blue dial, bracelet)

Reference 210.20.42.20.03.002 · $10,000–$25,000

This Seamaster on Amazon

Prices and availability change; the band above is a research figure, so check the current listing.

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