Short answer
Reference 210.30.42.20.01.001 is the Omega Seamaster Diver 300M with a 42 mm steel case, black ceramic dial, and steel bracelet. Omega fits calibre 8800 inside and rates the watch to 300 m. Retail runs about 5,900 USD to 6,200 USD. Replicas of this reference sell from about 50 USD to 550 USD, and the build quality at those two ends has little in common.
What each block of the number means
- 210: Seamaster Diver 300M family
- 30: steel case and bracelet
- 42: 42 mm case diameter
- 20: bracelet fitment, 20 mm at the lugs
- 01: black dial
- 001: first version of that dial
Genuine specs a replica has to copy
- Case: 42 mm wide, 13.6 mm thick, brushed sides with polished flanks
- Crystal: domed sapphire, anti-reflective coat on both faces
- Bezel: black ceramic insert, white enamel dive scale, scalloped steel edge
- Helium escape valve at 10 o'clock
- Dial: black ceramic with a laser-cut wave pattern, date at 6 o'clock
- Hands: skeletonized rhodium, lume fill, no cyclops over the date
- Movement: calibre 8800, co-axial escapement, 55 hour power reserve, 25,200 vph, METAS Master Chronometer
- Caseback: sapphire, wave-profiled edge, movement visible
- Bracelet: steel, push-button clasp with a diver extension
Checks that split the grades
Bezel
The genuine bezel turns in 120 clicks. Motion is firm and the triangle lands on 12. Low-grade replicas use a stamped insert with a printed scale, and the pip sits off center.
hippocampus replica 210.30.42.20.01.001
Dial
The wave pattern on the genuine dial is cut into ceramic. The ridges catch light at an angle and change with the wrist. A printed wave texture stays flat under the same light. Genuine lume is blue-green and matches across hands and markers.
Movement
Calibre 8800 runs at 25,200 vph, which is 3.5 Hz, or seven beats per second. An ETA 2824 or a clone of it runs at 28,800 vph, eight beats per second. Count the seconds hand for 10 seconds: 70 beats points to a 25,200 vph movement, 80 beats points to a 4 Hz base.
Caseback and bracelet
Genuine end links sit flush at the case with no gap. The clasp closes with a firm click and the diver extension slots in without play. On the caseback, engraving depth is even and the rotor shows a Cotes de Geneve arabesque finish.
Price tiers in the replica market
- Quartz builds: about 50 USD to 120 USD. Wrong beat rate, flat dial, mineral glass.
- Automatic builds on a 2824 clone: about 150 USD to 300 USD. Correct case size, printed wave texture, 4 Hz movement.
- High-grade builds: about 300 USD to 550 USD. 25,200 vph movement, ceramic dial, sapphire, matched lume.
Secondhand genuine pieces of this reference trade near 3,700 USD to 4,600 USD. Prices change with supply, so treat these numbers as a range, not a quote.
US legal position
US law treats counterfeit watches as trademark infringement. Sale or import can bring criminal charges under 18 U.S.C. 2320 and civil claims under the Lanham Act. US Customs and Border Protection can seize shipments. Personal use and resale are not the same offense, but import remains a seizure risk. This is a summary, not legal advice.