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The Encyclopedia of Horology

Wristwatch · Diver's wristwatch

Omega Seamaster 120 'Baby Ploprof' Reference 166.0250

Partially verified

This is a stainless steel Omega Seamaster 120 diver's wristwatch, commonly known as the 'Baby Ploprof', reference 166.0250, dating to circa 1979. The watch features an asymmetrical tonneau-shaped stainless steel case measuring 38 mm in width, fitted with a calibrated black rotating bezel and a steel Milanese mesh bracelet. Its black dial is printed with baton indices, depth ratings of 120m/400ft, a date aperture at 3 o'clock, and broad luminous hands. According to the seller, the wristwatch is powered by the 17-jewel Omega Calibre 1010 automatic mechanical movement.

Front view of the Omega Seamaster 120 ref. 166.0250 on wrist
Front view of the Omega Seamaster 120 ref. 166.0250 on wrist — Vintage Watch Specialist. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
vintagewatchspecialist.com
Category
Wristwatch · Diver's wristwatch
Maker / attribution
Omega
Reference
166.0250
Catalogue / lot identifier
vws4069
Source-reported date
c. 1979
Country
Switzerland

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case Construction and Exterior Hardware

The timepiece features a stainless steel case reported by the seller with a width of 38 mm, a lug height of 42 mm, and a lug width of 22 mm. The bezel is a calibrated rotating black insert with a luminous triangle marker visible at 12 o'clock.

A steel bracelet, described by the seller as an Omega Milanese mesh 'seatbelt' bracelet, is fitted to the case. The vendor lists the crystal material as sapphire.

Evidence for this section
  • “Width 38mm”
  • “Lug Height 42mm”
  • “Lug width 22mm”
  • “Crystal Sapphire”
  • “Completing the look is Omega’s iconic Milanese mesh “seatbelt” bracelet, giving the watch exceptional wrist presence while remaining incredibly comfortable.”
  • “Calibrated rotating black bezel with luminous triangle at 12 o'clock.”

Dial Configuration and Display

The matte black dial features baton hour indices and a framed date window at the 3 o'clock position. The hands are chunky, including a distinctive broad arrow minute hand.

Visible dial inscriptions include 'Omega', 'Seamaster', 'AUTOMATIC', '120 m/400ft', and 'SWISS MADE'. The vendor describes the hour markers as tritium indices.

Evidence for this section
  • “Matte black dial marked 'Omega', 'Seamaster', 'AUTOMATIC', '120 m/400ft', and 'SWISS MADE'.”
  • “Framed date window positioned at 3 o'clock.”
  • “Luminous baton hour markers and chunky luminous hands, including a broad arrow minute hand.”
  • “The matte black dial is beautifully preserved, with bold tritium indices and that unmistakable chunky handset—complete with broad arrow minute hand—now ageing to an attractive warm tone.”

Reported Movement and Technical Specifications

The mechanical movement is not visible in the provided image. The seller states the watch is powered by a mechanical automatic Omega Calibre 1010 featuring 17 jewels and an estimated 42-hour power reserve.

The reference is recorded as 166.0250 with a reported date of issue of circa 1979. The listing notes that neither original box nor papers are included.

Evidence for this section
  • “Calibre 1010”
  • “Jewels 17”
  • “Winding Automatic”
  • “Movement Type Mechanical”
  • “Power Reserve 42 hours”
  • “Date of Issue c.1979”
  • “Box No”
  • “Papers No”

Open research questions

  • What movement serial number is engraved on the Calibre 1010 movement to corroborate the circa 1979 production date?
  • Is the reported sapphire crystal a modern replacement or original factory specification for reference 166.0250?
  • What reference and date code markings are stamped on the interior of the case back and on the mesh seatbelt clasp?

Source evidence

Recorded claims and source quotations for Omega Seamaster 120 'Baby Ploprof' Reference 166.0250
FieldSource-reported valueSource quotation
Reference166.0250“Model Ref 166.0250”
Calibre1010“Calibre 1010”
Jewels17“Jewels 17”
Case MaterialStainless Steel“Case Stainless Steel”
Dial ColourBlack“Dial Black”
Width38mm“Width 38mm”
Lug Width22mm“Lug width 22mm”
CrystalSapphire“Crystal Sapphire”
Power Reserve42 hours“Power Reserve 42 hours”
Wrist Size185mm (Aprox)“Wrist Size 185mm (Aprox)”

Visible details

  • Matte black dial marked 'Omega', 'Seamaster', 'AUTOMATIC', '120 m/400ft', and 'SWISS MADE'.
  • Framed date window positioned at 3 o'clock.
  • Luminous baton hour markers and chunky luminous hands, including a broad arrow minute hand.
  • Calibrated rotating black bezel with luminous triangle at 12 o'clock.
  • Fitted to a stainless steel Milanese mesh bracelet.

Research qualifications

  • The internal mechanical movement and case back are not visible in the provided photograph.
  • Movement caliber and jewel count rely on seller descriptions.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Omega Seamaster 120 Baby Ploprof - Model Reference 166.0250 - On Mesh – Vintage Watch Specialist

Reviewed 2026-10-21 · Record a8671bb625

Terms in this record

Glossary explanations for terms named in this object’s record.

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