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The Encyclopedia of Horology

Marine chronometer · Key-winding marine chronometer

Ulysse Nardin Marine Chronometer No. 6903

Partially verified

According to the auction catalog, this marine chronometer by Ulysse Nardin dates to circa the late 1950s and features a key-winding movement with a 48-hour power reserve. The instrument is mounted in a brass bowl with gimbaled suspension inside a three-tier mahogany case equipped with gilt brass hardware and an exterior plaque reading 6903. The white dial displays Arabic numerals, an up/down state-of-wind indicator below 12 o'clock, and a subsidiary seconds register bearing the number 6903 in red. The source reports that the piece is accompanied by a wooden outer traveling box numbered 8609 and Japanese service paperwork from 1971.

Dial and gimbaled suspension of Ulysse Nardin Marine Chronometer No. 6903 in mahogany box
Dial and gimbaled suspension of Ulysse Nardin Marine Chronometer No. 6903 in mahogany box — Antiquorum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
catalog.antiquorum.swiss
Category
Marine chronometer · Key-winding marine chronometer
Maker / attribution
Ulysse Nardin
Reference
Not recorded
Catalogue / lot identifier
133
Source-reported date
circa late 1950s
Country
Switzerland
Source-reported serial
6903

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

Dial and Visual Identification

The white dial features Arabic numerals with an up-and-down power reserve indicator positioned below the 12 o'clock marker. A subsidiary seconds dial is located at 6 o'clock, which includes the identifier '6903' printed in red. The dial and brass bowl assembly measure approximately 12 cm in diameter.

The source provides a condition grading for the dial, noting it as 'Good' with slight scratching.

Evidence for this section
  • “White dial with Arabic numerals, an up-and-down power reserve indicator below 12 o'clock, and subsidiary seconds dial at 6 o'clock with '6903' printed in red.”
  • “Diameter Dial/bowl: 12cm (approx.)”
  • “Dial: 3-8-01 Good Slightly scratched”

Construction and Housing

The chronometer is housed within a three-tier mahogany case featuring gilt brass handles. The assembly includes a middle section with a hinged lid containing a glass viewing port, protecting the gimbaled suspension and brass bowl. The wooden exterior case is reported to show signs of oxidation and scratches.

The instrument is accompanied by an outer wooden traveling box.

Evidence for this section
  • “housed in a three-tier mahogany case with gilt brass handles, featuring a middle section with a hinged lid and glass viewing port, a brass bowl, and a gimbaled suspension.”
  • “Case: 3-6-8 Good Slightly oxidized Slightly scratched”
  • “Accompanied by a Ulysse Nardin (UN) wooden transportation case.”

Mechanism and Provenance

The timepiece utilizes a key-winding movement specified with a 48-hour power reserve. The source recommends an overhaul for the movement.

The instrument includes an outer wooden traveling box numbered 8609. Documentation provided includes service records from Kajihara Kokisho Co., Ltd., based in Shimonoseki, Japan, dated September 10, 1971.

Evidence for this section
  • “A fine and rare key-winding marine chronometer with a 48-hour power reserve.”
  • “Movement: 3* Good Overhaul recommended, at buyer's expense”
  • “UN 8609 Travelling outer box (wood, 32.5 x 26.5 x24cm); Kajihara Kokisho Co.,Ltd, Shimonoseki, Japan service papers dated 10 Sep 1971”

Open research questions

  • What is the significance of the differing serial numbers on the instrument (6903) and the outer traveling box (8609)?
  • Do the 1971 Japanese service records specify the nature of the overhaul required or performed?

Source evidence

Recorded claims and source quotations for Ulysse Nardin Marine Chronometer No. 6903
FieldSource-reported valueSource quotation
Case Number6903“Case No. 6903”
Power Reserve48-hour“48-hour power reserve”
Case DescriptionThree-tier mahogany case“housed in a three-tier mahogany case with gilt brass handles”
Dial/Bowl Diameter12cm (approx.)“Diameter Dial/bowl: 12cm (approx.)”
Outer BoxUN 8609 Travelling outer box“UN 8609 Travelling outer box (wood, 32.5 x 26.5 x24cm)”
Estimated Datingcirca late 1950s“Year circa late 1950s”
Case Number6903“Case No. 6903”

Visible details

  • White dial with Arabic numerals, an up-and-down power reserve indicator below 12 o'clock, and subsidiary seconds dial at 6 o'clock with '6903' printed in red.
  • Brass bowl with gimbaled suspension housed within a hinged mahogany inner box.
  • Oval metal plaque on the front of the inner wooden case engraved with '6903'.
  • Gilt brass drop handle visible on the side of the wooden case.

Research qualifications

  • The internal movement is not uncased or shown in the primary photograph.
  • The date 'circa late 1950s' is an auction house estimate and not independently marked on the visible dial.

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

Consulted source

ULYSSE NARDIN, MARINE CHRONOMETER, WOOD | Important Modern & Vintage Timepieces | Hong Kong May 31, 2026

Reviewed 2026-10-25 · Record 43f0aa5935

Terms in this record

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