Reference guide

OMEGA references

14 OMEGA references, each one built from what OMEGA itself publishes about that reference — case, movement, water resistance, bracelet — with what a dealer should check before buying one.

Where OMEGA states nothing, these pages say so rather than filling the gap. Last reviewed 2026-09-23.

Constellation

Constellation Co-Axial Master Chronometer 41mm, white dial131.30.41.21.04.001Forty-four millimetres lug to lug on a forty-one millimetre case. Three millimetres of total overhang, where most watches here run six to ten.Specifications

De Ville Prestige

De Ville Prestige Co-Axial Master Chronometer 40mm, green dial434.10.40.20.10.001The same calibre as the Diver 300M, in a case rated to thirty metres instead of three hundred. A useful reminder that depth lives in the case, not the movement.Specifications

Seamaster 300

Seamaster 300 Co-Axial Master Chronometer 41mm, blue dial234.30.41.21.03.002Three hundred metres, like the Diver 300M — and a different calibre, a different case and a different watch. The name overlap is the trap.Specifications

Seamaster Aqua Terra 150M

Seamaster Diver 300M

Seamaster Diver 300M 42mm, black dial210.30.42.20.01.001OMEGA's actual dive watch: 300 metres, calibre 8800 running at 3.5 Hz with 55 hours. A higher beat rate and a shorter reserve than the Aqua Terra, and a different movement family entirely.Specifications

Seamaster Planet Ocean 6000M

Ultra Deep 6000M, O-MEGASTEEL, 45.5mm, blue dial215.30.46.21.03.002Six hundred bar, 254 grams and 18 millimetres of case. Every published number on this reference is an outlier, and the buyer needs all of them in advance.Specifications

Seamaster Planet Ocean 600M

Planet Ocean 600M Co-Axial Master Chronometer 42mm, black dial217.30.42.21.01.001Sixty bar and a flat crystal rather than a domed one, with a diver extension in the clasp. Every one of those is a deliberate choice you can test.Specifications

Seamaster Railmaster

Railmaster Co-Axial Master Chronometer 38mm, grey dial235.10.38.20.06.001Thirty-eight millimetres and under forty-five lug to lug, on the only calibre 8806 documented here. The smallest OMEGA on this site by some way.Specifications

Speedmaster '57

Speedmaster '57 Co-Axial Master Chronometer Chronograph 40.5mm332.10.41.51.01.001Manual winding with sixty hours, which is an unusual pairing. Winding it by hand is also the most informative thirty seconds of the inspection.Specifications

Speedmaster Chronoscope

Speedmaster Chronoscope 43mm, blue dial329.30.43.51.03.001OMEGA publishes a lug-to-lug figure and a weight for this reference but no case thickness. Where the maker is silent, so is this page.Specifications

Speedmaster Dark Side of the Moon

Dark Side of the Moon, black ceramic, 44.25mm310.92.44.51.01.004Ceramic case, ceramic buckle. Ceramic does not scratch and does not polish; it chips, and that is the only failure mode you are grading for.Specifications

Speedmaster First OMEGA in Space

First OMEGA in Space 39.7mm, blue-grey dial310.30.40.50.06.001A sapphire crystal shaped like hesalite. It looks like the soft plastic dome buyers expect and behaves nothing like it, which cuts both ways.Specifications

Speedmaster Moonwatch Professional

Speedmaster Moonwatch Professional 42mm, Hesalite310.30.42.50.01.001The Hesalite Moonwatch. Same calibre and case as its sapphire sibling, a different crystal, and a different reference number — which is the only reliable way to tell which one you are being offered.Specifications

Not affiliated with OMEGA. Specifications are read from the manufacturer's own published documentation on the date shown on each page and may change; the manufacturer's current documentation governs.