A Co-Axial chronograph before the in-house era
In the late 1990s and early 2000s Omega rolled out the Co-Axial escapement (designed by George Daniels and licensed to Omega) across its mechanical line. For 3-hand watches the rollout was straightforward via the Cal. 2500 and later the in-house Cal. 8500. For chronographs Omega initially modified the Frédéric Piguet Cal. 1185 (a high-grade automatic chrono base used by Blancpain, Breguet, and others) with the Co-Axial escapement and Omega's own balance, branding it the Cal. 3303.
In the Speedmaster Broad Arrow Co-Axial
The Cal. 3303 powered the Speedmaster Broad Arrow Co-Axial (ref. 3551.20.00 and variants, 2007-2011), a 42 mm Speedmaster that revived the broad-arrow handset of the original 1957 CK 2915 but with a modern automatic chronograph caliber. It also powered selected De Ville Co-Axial Chronograph references in white and rose gold during the same period. The 3303 was Omega's first Speedmaster caliber to combine the Co-Axial escapement with chronograph functionality, several years before the in-house Cal. 9300 arrived in 2011.
Why FP base, not in-house
In 2007 Omega did not yet have an in-house automatic chronograph caliber. The Frédéric Piguet 1185 was the highest-grade outsourced automatic chronograph available in the Swatch Group ecosystem (Frédéric Piguet was at that point a Blancpain manufacture, sister-company to Omega within Swatch). Modifying the FP 1185 with the Co-Axial escapement was an interim solution: it gave Omega the marketing position of "Co-Axial chronograph" while in-house development of the 9300 family continued. The 3303 ran for about four years before the in-house architecture was ready.
What replaced it
In 2011 Omega launched the Cal. 9300, the brand's first fully in-house automatic chronograph, in the new Speedmaster Co-Axial Chronograph (38 mm and 44 mm references). The 9300 brought 60-hour reserve, 12-hour totaliser at 3 + 60-min counter at 3 (intuitive single-subdial chronograph display), and a column wheel and vertical clutch architecture designed entirely by Omega. The 3303 was retired from current production but remains in service through Omega's service network for 2007-2011 watches.
Where it sits
The 3303 is a transitional Speedmaster caliber: chronograph + Co-Axial in a single watch, before Omega could deliver this combination in-house. For collectors of the Speedmaster Broad Arrow Co-Axial (2007-2011 references) the 3303 is the original engine and remains fully serviceable. Used Speedmaster Broad Arrow Co-Axial references trade on the secondary market at USD 2,800-4,200, representing strong value for an automatic Co-Axial chronograph from Omega's Speedmaster line.