Rolex 2765 Oyster Chronometer

A checked version of this page, approved on 23 August 2026, was based on this revision.

Oyster → 2765

The 2765 is a manual-wind steel Oyster made around the late 1930s and early 1940s. It appears on some collector Bubbleback lists, but the auction record does not support that classification: the documented movements are manually wound, with no Perpetual rotor.

Auction catalogues apply several names to the reference, including Oyster Chronometer, Chronomètre, Oyster Royal, Oyster Scientific, Oyster Gammeter and Observatory. Some are visible on photographed dials; others are catalogue model labels and should not be read as confirmed dial signatures.

Core facts

detail	value
reference	2765
family	Oyster (manual-wind)
production	no documented range; auction catalogues date individual examples from circa 1939 to circa 1942
case diameter	32mm
case construction	steel tonneau; one Antiquorum example described as two-body; screw-down back and crown
caseback	screw-down; flat profile reported in secondary listings, not established across the auction record
bezel	smooth, polished
crystal	material not established by the cited auction catalogues
crown	screw-down
winding	manual
movement	10 to 10½ lignes, rhodium-plated, 17 or 18 jewels, straight-line lever
movement grades documented	Ultra Prima (6 positions); 17-jewel adjusted to 7 positions; 18-jewel
seconds	centre seconds on some variants
case materials	stainless steel on eight documented watches
catalogue designations	Oyster Chronometer / Chronomètre, Oyster Royal, Oyster Scientific, Oyster Gammeter, Observatory; additional secondary-listing names remain unverified
retailer variants	Murdock's, Cape Town

Where it sits in the line

Rolex continued making hand-wound Oysters after the Perpetual arrived. Hodinkee's Bubbleback collecting guide describes these parallel manual-wind watches as “flatbacks.” Ref. 2765 belongs to the manual branch: all three Antiquorum descriptions and the Bonhams catalogue texts specify manual winding.

Antiquorum dated two examples to the 1930s and one to the 1940s. Bonhams dates individual watches to circa 1939, circa 1940 and circa 1942. These estimates place the known watches near the turn of the decade but do not establish start and end years for the reference.

The numerically adjacent ref. 2764 is automatic. Ref. 2765 is not. Their proximity and similar 32mm tonneau outlines do not show that they share movements or caseback construction.

Production outline

Three Antiquorum lots span sales from 1995 to 2009. Bonhams accounts for five more watches across seven appearances between 2019 and 2023. Two Bonhams watches were reoffered, so the ten auction appearances represent eight watches rather than ten.

Neither the start nor the end of the run is documented. The Antiquorum catalogues publish no case numbers; several Bonhams records do. Three sit close together, 90501 on the 1939-dated Oyster, 90751 on the Oyster Scientific and 90939 on the Oyster Gammeter, and a fourth sits far above them on the Oyster Royal, published only as 133***. Four numbers are a scatter rather than a range, and they cannot date the reference on their own. They should not be turned into a production range.

Movement notes

Every documented 2765 is hand-wound. The Antiquorum lots describe movements of 10 to 10½ lignes, rhodium-plated, with a straight-line lever escapement, in three configurations.

The Milan 1995 example carried a 10-ligne Ultra Prima, 17 jewels, anchor escapement, monometallic balance with Breguet hairspring, regulated across six positions and temperatures. The Hong Kong 2001 example carried a 10½-ligne with 17 jewels, Rolex Superbalance and a self-compensating Breguet balance-spring, adjusted to seven positions. The New York 2009 example carried a 10½-ligne with 18 jewels, a straight-line lever and a Superbalance adjusted to six positions.

Bonhams splits its five watches between two jewel counts and gives no ligne sizes. The Oyster Royal runs a 17-jewel manual wind with Rolex's patented Super Balance, the Oyster Gammeter a 17-jewel manual wind, the Oyster Scientific and the 1939 Oyster an 18-jewel manual wind timed to six positions each, and the Observatory an 18-jewel manual-wind chronometer. One cataloguing slip is worth knowing about before searching that archive: Bonhams titled the Gammeter lot a stainless steel automatic wristwatch, while its own description of the same lot reads "17-jewel manual wind". The title is the error. Nothing in the record supports a self-winding 2765.

“Ultra Prima” is a movement grade, not a caliber. David Boettcher's history of Rolex and Aegler movement grades dates Wilsdorf's registration of the name to 9 December 1930. Boettcher notes that the distinction between Extra Prima and Ultra Prima is unclear. The Milan 2765 is described as Ultra Prima with 17 jewels.

Neither Antiquorum nor Bonhams names a caliber. Secondary listings identify Cal. 700, but no movement photograph with a visible caliber marking or Rolex technical document has been found. The attribution remains unverified.

Dial map

The eight catalogued watches show several dial layouts. That variety documents watches as sold; it does not by itself prove factory delivery or a production sequence.

The Milan 1995 dial is silver and rose-coloured, with printed Arabic numerals and indices and burnished steel leaf hands. The Hong Kong 2001 dial is bronze-coloured with mixed radium-coated Arabic and Roman numerals, triangular and bâton indexes, and radium-coated "skeleton" hands; Antiquorum graded the dial 4-7-01 and the watch overall A (Good). The New York 2009 dial is copper-coloured with luminous Arabic numerals and an outer one-fifth-seconds track carrying five-minute Arabic markers, paired with luminous blued steel baton hands.

The Bonhams watches widen the range again. Its Oyster Royal is silvered, with luminous-filled Arabic numerals, an outer one-fifth-seconds track carrying Arabic five-minute markers, and blued steel Mercedes hands with luminous inserts. The Oyster Gammeter is two-tone salmon pink, with luminous baton hour markers, gilt inner Arabic quarters and blued steel pointed baton hands. The Oyster Scientific is two-tone silvered with black baton and Arabic markers and black leaf hands. The 1939 Oyster carries applied gilt Arabic numerals on silver, blued steel sword hands and a red centre seconds hand. The Observatory is the odd one out: two-tone silvered, luminous 1–12 Arabic numerals with a red 12–24 ring inside them, and subsidiary rather than centre seconds.

Secondary listings add other layouts, including a sector dial and a watch described as tropical, but those records are leads rather than evidence of factory variants.

Antiquorum uses Oyster Chronometer and Oyster Chronomètre. Bonhams catalogues watches as Oyster Royal, Oyster Scientific, Oyster Gammeter and Observatory. Catalogue model fields are not always literal dial transcriptions, so only wording visible in photographs should be treated as dial text. Oyster Precision and Ultra Prima appear in secondary listings and remain lower-confidence additions.

Case, bezel, crystal, and crown

The catalogued watches have steel tonneau cases around 31–32mm. Antiquorum describes its Hong Kong example as a two-body case, polished and brushed, with a screw-down back and crown. That construction should not be generalized to every example. The crystal material is not stated.

Secondary listings call ref. 2765 a flat-back Oyster, and no auction description calls it a Bubbleback or documents a self-winding movement. The manual movements are enough to reject the Bubbleback classification. The precise caseback profile still needs a clearly identified side or rear photograph before it can be stated for every watch.

All eight catalogued watches are steel. That does not prove the reference was made only in steel.

Bracelets, end links, and clasps

No original-delivery Rolex bracelet is documented for the reference. Two Bonhams watches, the Oyster Royal and the 1939 Oyster, came on steel link bracelets with folding clasps, but Bonhams calls both associated, which records what the watch wore into the saleroom rather than what left the factory with it. The Hong Kong 2001 example came with a steel Rolex buckle and fitted box. No bracelet reference or end-link number is documented.

Retailer variants

One is documented: the New York 2009 example was retailed by Murdock's of Cape Town and carries the retailer's signature. A single watch does not establish how widely Murdock's sold the reference.

Auction record

Venue	Date	Lot	Dial	Movement	Result
Antiquorum, Milan	1995-05-22	160	Silver and rose, printed Arabic, leaf hands	10′′′ Ultra Prima, 17j, 6 positions and temperatures	Not recorded; catalogue scaling is ambiguous
Antiquorum, Hong Kong	2001-06-08	257	Bronze, mixed radium Arabic and Roman, skeleton hands	10½′′′, 17j, Superbalance, 7 positions	HKD 23,000 (est. HKD 20,000–23,000)
Antiquorum, New York	2009-12-09	217	Copper, luminous Arabic, 1/5th-seconds track	10½′′′, 18j, straight-line lever, Superbalance, 6 positions	USD 1,560 (est. USD 1,500–2,500)
Bonhams, London Knightsbridge	2019-02-19	50	Silvered, luminous Arabic, Mercedes hands (Oyster Royal, case 133***)	17j Super Balance, manual	Unsold (est. GBP 500–700)
Bonhams, London Knightsbridge	2019-05-21	74	Two-tone salmon pink, luminous batons (Oyster Gammeter, case 90939)	17j, manual	GBP 2,805 incl. premium
Bonhams, London Knightsbridge	2019-05-21	75	Two-tone silvered, black batons and Arabic (Oyster Scientific, case 90751)	18j, manual, 6 positions	Unsold (est. GBP 1,200–1,800)
Bonhams, London Knightsbridge	2019-05-21	88	Silvered, luminous Arabic, Mercedes hands (Oyster Royal, case 133***)	17j Super Balance, manual	GBP 637.50 incl. premium
Bonhams, London Knightsbridge	2019-11-19	37	Two-tone silvered (Oyster Scientific, case 90751, re-offered)	18j, manual, 6 positions	GBP 4,062.50 incl. premium
Bonhams, London Knightsbridge	2022-09-13	27	Silvered, applied gilt Arabic, red centre seconds (Oyster, case 90501)	18j, manual, 6 positions	GBP 2,550 incl. premium
Bonhams, Online New York	2023-06-20/30	27	Two-tone silvered, red 12–24 inner ring, subsidiary seconds (Observatory)	18j, manual, chronometer	USD 3,840 incl. premium

Seven Bonhams appearances cover five watches: the Oyster Royal went unsold at Knightsbridge in February 2019 before selling there in May, and the Oyster Scientific did the same between May and November of the same year.

The Hong Kong 2001 lot came with a fitted box and a full Antiquorum condition grade of A (Good), case 4-6, movement 4-6* and dial 4-7-01. It also came with a literature citation. Antiquorum noted that a similar watch is published in Osvaldo Patrizzi's Rolex, Collecting Wristwatches (Guido Mondani Editore, Genova, 1998) at page 278. The citation says “a similar watch,” not ref. 2765 by number, and the cited page has not been checked directly.

The Milan catalogue's lire figures have unclear scaling, so they are not reproduced as a sale result. The remaining prices span different dial conditions, accessories and sale formats and do not form a reliable price series.

Related references

Bubbleback 2764 — the automatic neighbour, Cal. 620N
Oyster Royal 2574 — pre-war manual Oyster, boy's size
Oyster Royal 1873 — manual flat-back Oyster, shares the "Scientifical" dial vocabulary
Oyster Perpetual 2240 — self-winding contemporary with provisional Bubbleback classification
Bubbleback 1858 — the first Oyster Perpetual, 1933

Sources