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Omega Seamaster 120 (Ref. 166.073) “Deep Blue”, 1970 — view 1 of 6
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Omega Seamaster 120 (Ref. 166.073) “Deep Blue”, 1970

DocumentedDocumented from a dealer's listing; attribution and date as stated by the dealer.
Maker / attribution
Omega (maker)
Date
1970
Country of origin
Switzerland
Object type
Wristwatch
Stock no.
OMSM120DB-3
Credit line
Dealer listing, Craft & Tailored (OMSM120DB-3)
Catalogue title (original)
1970 Omega Seamaster 120 (Ref. 166.073) “Deep Blue” (English)

View the source record (dealer listing) ↗ (opens another website in a new tab)Suggest a correction

Record summary

Catalogued by Craft & Tailored (dealer), Los Angeles (stock number OMSM120DB-3), this is a wristwatch by Omega, made in Switzerland, dated 1970. The Atlas places it in the Quartz Revolution period (1969 – 1990) of its Wristwatches collection. The record is illustrated with 6 photographs.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

Dealer description — Craft & Tailored

There is something about the early vintage Omega Seamaster that truly embodies the golden era of dive watches of the 1960s-1970s. Omega has a long history and heritage in dive watches dating back to the 1930s. The seahorse-adorned case back of the Seamaster series pays tribute to Neptune, the Roman god of the sea. The seahorse logo was conceived by engraver Jean-Pierre Borle. He was inspired by an image of Neptune driving a chariot pulled by seahorses, which is why the Omega seahorses are depicted wearing bridles. The "Deep Blue" Omega Seamaster 120 ref. 166.073 is a stunning timepiece that is both functional and stylish. Its combination of beauty, history, and performance makes it a true collector's item, and a watch that you can be proud to wear for years to come. The defining difference between the Omega Seamaster Deep Blue and other dive watches of the era is execution, with an overall design that feels very familiar but with an aesthetic that outclasses its counterparts. As it was only produced for 4 years, from 1970 to 1974, the Deep Blue is certainly an uncommon timepiece and one of the most sought-after sports watches among Omega collectors. Stock # OMSM120DB-3 Brand Omega Style Seamaster 120 Model 166.073 Serial 29XXXXXX Size Men's Material Stainless Steel Dial Blue Millimeters 42.5 Bracelet Omega 1170 Bracelet W/ 634 End Pieces CASE & BRACELET The broad lugged and stout case features a rounded finish that achieves a robust appearance that is large yet ergonomic while sitting on the wrist. The case appears to remain unpolished with honest wear and the original profiling and dimensions remain fully present. The original blue bakelite bezel is beautifully persevered, showing gentle wear which is expected, but no cracking or delamination is present. The case retains its large Omega-signed screw-down crown, which also operates the quick-set date function by pulling the crown out to the last position. The case back features the Seamaster medallion in deep and crisp condition, with no evidence of previous polishing present. The Omega 1170 bracelet with 634 end pieces retains 17 links that show light stretch and will fit up to a 6 1/4-inch wrist. DIAL & HANDS The original blue dial remains in exceptional condition and features no distortion to the gloss finish or damage. The tritium lume plots have achieved a lovely golden-yellow patina and exhibit no apparent degradation when inspected under UV light. The original tritium sword-style hands have aged similarly to the dial, under UV light inspection the hour hand features some superficial cracking and remains stable, while the hour and second's hand exhibit no degradation. ACCESSORIES

Historical context

Quartz Revolution (1969 – 1990)

Seiko's Astron begins mass quartz timekeeping; traditional industries contract sharply.

Quartz and digital watches transformed the market after 1969. Swiss employment collapsed, Japanese and Hong Kong production soared, and the Swatch (1983) helped the Swiss industry recover; mechanical watches survived as luxury goods.

Read the period in the timelineMore wristwatches from this periodEarlier: Modern Mechanical Horology

Atlas type guide

Dive and water-resistant watches

Keeping water and dust out of a wristwatch was a long-standing challenge. Rolex's screw-down Oyster case (1926) and Omega's Marine (1932) were landmarks; in the early 1950s Blancpain's Fifty Fathoms and Rolex's Submariner defined the professional dive watch with rotating bezels for timing dives, luminous dials and high water resistance. The ISO 6425 standard (1982) later codified what a 'diver's watch' must do.

Dive watches became icons of post-war design and exploration, and their evolution — helium escape valves, ceramic bezels, saturation-diving depth ratings — records the history of underwater work.

What to look for

  • Unidirectional or bidirectional rotating bezel with minute markings.
  • Screw-down crown and case back; depth rating printed on the dial.
  • Luminous hands and markers (radium before c. 1960, tritium c. 1960–1998, then Super-LumiNova).
  • Reference numbers on the case between the lugs or inside the back.

Dating clues

  • Screw-down Oyster cases: from 1926.
  • Professional dive watches: from 1953.
  • Tritium 'T' marks on dials: c. 1960–1998.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

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