Rolex 2765 Oyster Chronometer

Oyster -> 2765

The 2765 is a manual-wind Oyster of the late 1930s and early 1940s, and it is the cleanest demonstration in the whole early-Oyster catalogue of what actually makes a Bubbleback a Bubbleback. The case is the same 32mm tonneau that the contemporary Oyster Perpetuals wear. The lugs, the bezel, the screw-down crown are the same. The caseback is flat. Rolex domed the back of a Bubbleback to clear a Perpetual rotor; the 2765 has no rotor to clear, so it does not get the dome. Collector reference lists have filed the 2765 among the Bubblebacks for years on the strength of that shared silhouette, and every documented example contradicts them.

The second oddity is the dial text. At least eight Rolex model names are documented on this one reference number: Oyster Chronometer, Oyster Chronomètre, Oyster Royal, Oyster Scientific, Oyster Precision, Ultra Prima, Oyster Gammeter and Observatory. Rolex was still using dial text to advertise which grade of movement a buyer was getting rather than which model he had bought.

Core facts

detail	value
reference	2765
family	Oyster (manual-wind)
production	1930s–1940s; no firm start or end year documented
case diameter	32mm
lug-to-lug	about 39mm
thickness	about 11mm
case construction	two-body, polished and brushed
caseback	flat, screwed down
bezel	smooth, polished
crystal	acrylic
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 (all documented examples)
dial designations	Oyster Chronometer / Chronomètre, Oyster Royal, Oyster Scientific, Oyster Precision, Ultra Prima
retailer variants	Murdock's, Cape Town

Where it sits in the line

Rolex did not stop making hand-wound watches when the Perpetual arrived in 1933. It ran two lines side by side for the better part of two decades. Hodinkee's Bubbleback collecting guide makes the point directly, describing the "flatbacks" that sat alongside the automatics of the period: manual-wind watches, and even early chronographs. The 2765 belongs to that parallel line, and it wears the Oyster case of its automatic contemporaries.

Placing it precisely inside that line is harder than it should be, because the auction record disagrees with itself about when the watch was made. Antiquorum dated its Hong Kong and New York examples to the 1930s and its Milan example to the 1940s. Bonhams is both more specific and more consistent, dating its examples circa 1939, circa 1940 and c.1942. Dealer listings put the run at roughly 1936 to 1942. A serial that circulates without catalogue backing, 133596, dated to 1941, now has rough company in the Bonhams Oyster Royal, whose case number the catalogue published as 133***. The honest position is that the 2765 is a late-1930s-into-the-war reference whose exact span nobody has published.

What is clear is the relationship to its automatic neighbours. The numerically adjacent 2764 is a Bubbleback proper: Cal. 620N, domed caseback, sub-seconds, "Super Precision" on the dial. The 2765 sits one digit away with the same case diameter and an entirely different architecture behind it. Rolex was allocating reference numbers by case and market position, not by movement type, which is exactly why a list built from reference numbers alone gets the family wrong.

Production outline

Documentation is thin, and for a long time it looked thinner than it is. Three Antiquorum lots span fourteen years of sales, Milan in May 1995, Hong Kong in June 2001 and New York in December 2009. Bonhams accounts for five more watches across seven appearances between February 2019 and June 2023, six of them at Knightsbridge and one in an online New York sale of a private Canadian collection. Below those sits a scatter of dealer listings that establish variants but carry no catalogue authority.

Neither the start nor the end of the run is documented, but the case-number picture is no longer blank. The Antiquorum catalogues published no case numbers; the Bonhams ones 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, but they are the first case-number evidence it has had. For a watch made in reasonable quantity across at least half a decade the public record is still poor, and the reason is probably that the 2765 spent the entire Bubbleback-collecting boom of the 1980s and 1990s being catalogued as something else.

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 adds 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 not a caliber. It is the top name in the grade hierarchy Aegler applied to the better movements it supplied to Rolex, running Prima, Extra Prima, Ultra Prima. David Boettcher's research at vintagewatchstraps.com traces the first Prima markings to the 1920s and dates Hans Wilsdorf's registration of "Ultra Prima" to 9 December 1930. What the grades actually bought is less settled than the names suggest. Boettcher finds the graded movements otherwise identical to standard ones, which puts the difference in adjustment work, to poise and isochronism, rather than in the design. He sees Prima on 15-jewel movements timed in six positions, and both Extra Prima and Ultra Prima on 18-jewel movements, and says the gap between the top two grades is not clear. The Milan lot sits outside that pattern: an Ultra Prima with 17 jewels.

Neither the Antiquorum nor the Bonhams catalogues name a caliber number for the 2765. Dealer listings routinely identify the movement as Cal. 700, an 18-jewel adjusted to six positions, which matches the New York 2009 lot's jewel count and position count exactly. That is not the same as confirmation. Until a movement photograph with a visible caliber marking or a Rolex parts document surfaces, the ligne size and the grade are what the record supports. Cal. 700 stays unverified.

Dial map

The 2765 produced a wide dial range, and the catalogued examples barely repeat themselves. The three Antiquorum lots alone show three quite different watches.

Silvered and rose two-tone dial with printed Arabic numerals and burnished steel leaf hands, on the 10-ligne Ultra Prima example sold at Antiquorum Milan in May 1995.

Bronze-coloured dial with mixed radium Arabic and Roman numerals, bâton indexes and radium skeleton hands. Antiquorum Hong Kong, June 2001.

The Milan 1995 dial is silver and rose-coloured, with printed Arabic numerals and indices and burnished steel leaf hands, the most restrained of the three and the most obviously a dress watch. 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.

Beyond the auction record, dealer listings add a two-tone silvered configuration with black baton markers and alternating Arabic numerals, a sector dial, and at least one tropical example from 1941 in the United Kingdom. Blued steel dagger hands with centre seconds recur on the Scientific and Royal variants.

The dial designations are the reference's real signature. The same case appears marked Oyster Chronometer, Oyster Chronomètre, Oyster Royal, Oyster Scientific, Oyster Precision and Ultra Prima, and Bonhams adds two more names to the pile, cataloguing one example as Oyster Gammeter and another simply as Observatory. Rolex was naming the watch after the grade of movement inside it, which is why a single reference number can carry at least eight different lines of dial text. The "Oyster Scientific" marking is the same vocabulary as the salmon "Scientifical" dial Antiquorum documented on the near-contemporary ref 1873 in 2024. Hodinkee's Bubbleback guide puts the word on a third watch, a manual-wind flatback ref 3009 with a white enamel sector dial that it calls a Rolex Scientific, which places the term across at least three manual Oysters of the period.

Case, bezel, crystal, and crown

Two-body stainless steel, polished and brushed, tonneau-shaped, 32mm across, roughly 39mm lug-to-lug and about 11mm thick. Bonhams gives 32mm for four of its five examples and 31mm for the Oyster Scientific. Screwed-down caseback and screw-down crown, which is what earns the Oyster name. Smooth polished bezel. Acrylic crystal, as the era requires.

The caseback is the whole story. It is flat. Every listing that troubles to describe it says so, several of them in the listing title, and neither the Antiquorum nor the Bonhams descriptions mention a domed or bulged back on any example. Bonhams records a screw-down back and crown on four of its five. A 2765 offered as a Bubbleback either has the wrong caseback fitted or is being described by someone working from a reference list rather than from the watch.

Stainless steel is the only case material documented. No gold, gold-shell or two-tone example appears in the record. With eight catalogued watches behind that statement rather than three it carries more weight than it used to, though not enough to call the reference steel-only.

Bracelets, end links, and clasps

No original Rolex bracelet is documented on the reference. None of the three Antiquorum lots was sold on one. Two of the Bonhams watches, the Oyster Royal and the 1939 Oyster, did come 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. Signed hardware is not absent altogether: the Hong Kong 2001 example came on a stainless steel Rolex buckle and with a fitted box, and Bonhams notes the cases of those same two watches as signed Oyster Watch Co.

Retailer variants

The Murdock's, Cape Town retailer signature sits below centre, under the Rolex Oyster Chronometre dial text.

One is documented so far: the New York 2009 example was retailed by Murdock's of Cape Town and carries the retailer's signature. None of the Bonhams lots records a retailer signature. Retailer-signed Rolex of this period is its own collecting category, and a South African signature is uncommon, but a single example establishes that Murdock's carried the reference and nothing more.

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	ITL 2,990 (est. ITL 2,500–3,000), as printed
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 remains the best-documented single example, and the money is the least of it. It 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. That citation is the only published-book grounding to surface for this reference so far, and its wording is careful: the catalogue says "a similar watch", not this reference by number.

The New York 2009 result at USD 1,560 against a USD 1,500–2,500 estimate says something about where the manual Oysters sat in the market at that point, landing at the bottom of the estimate in a year when steel sports Rolex was already climbing hard. Milan 1995 is harder to read. The catalogue prints an estimate of ITL 2,500–3,000 against a sold price of ITL 2,990, figures that cannot be taken at face value in 1995 lire and that the catalogue does not scale. They are reproduced above exactly as printed. The Bonhams results a decade later run from GBP 637.50 to GBP 4,062.50 inclusive of premium, a spread wide enough that no single figure represents the reference.

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
Bubbleback 2240 — self-winding contemporary
Bubbleback 1858 — the first Oyster Perpetual, 1933