The horological rabbit hole — which many collectors willingly fall delighted victim to — is a long one, lined with a seemingly endless number of watchmakers and references to immerse yourself in. Soon after having your interest sparked by that first great watch, it’s not uncommon to find yourself on an insatiable quest for further knowledge, a pursuit as admirable and advisable as they come in the collecting world. Once becoming familiar with all the names, dates, and models of note, the logical progression is to brush up on your understanding of important movements, of which the Cal. 33.3 most certainly is one. Those looking to do so will want to keep reading, as we’re about to break down the origins and significance of the legendary caliber.

Should the Cal. 33.3’s existence be news to you, allow us to break it down. Simply put, it’s a chronograph movement of the absolute highest grade, and one believed to have laid out the framework for similarly highly regarded chronographs of future years. Its story begins unsurprisingly in Switzerland, with two respected watchmakers. Back in 1930, Omega and Tissot formed one of the earliest horological conglomerates through the establishment of the Société Suisse pour L’Industrie Horlogère (SSIH). Two years later, Lemania and A. Lugrin Co would also join, setting out as one entity with the goal of producing precision complications of previously unseen quality.

Most notably, SSIH focused their efforts on the development and production of chronograph calibers, partially as a result of an increased interest in this complication following Omega’s timing of the 1932 Summer Olympics in Los Angeles. Like other great chronographs, the Cal. 33.3 drew inspiration from an already admired movement – The smaller brother / Lemania 13CH-based Cal. 28.9. In an attempt to advance the industry and conventions surrounding wristwatch sizing, the new caliber measured 15 lignes across, or 33.3 mm, earning it its name. The number 33 was also significant in that the caliber first emerged in 1933, affording the movement some appeal in numerological circles.

After its introduction, the chronograph saw implementation inside references from both Omega and Tissot, many of which featured oversized steel cases, and multi-scale dials. Though that does indeed equate to desirability in today’s market, it’s important to note what brought about this development. Essentially, this shift towards the greater production of robust timepieces can be attributed to the increased demand for chronographs in professional applications, where precise, legible timekeepers made all the difference. Such multi-scale variants were less so seen as works of horological art, and instead as tools intended to serve doctors, engineers, and other demanding professionals.

Furthermore, a great deal of the Cal. 33.3’s appeal in the eyes of collectors stems from the pivotal role it played in progressing Omega’s lineup of chronograph calibers. Upon mention of the words “Omega” and “chronograph,” images of the famed Cal. 321 which powered the earliest Speedmaster references will come to the minds of vintage-focused individuals. What many fail to recognize, is that without the Cal. 33.3, there would be no 321, making it an immensely substantial mechanism in not only Omega’s history, but the history of the chronograph as a whole.

All in all, it doesn’t get much better than the 33.3. Between its perfect proportions, industry advancing standards, and historical significant, there’s a whole heck of a lot to love. The range of exciting watches it would go on to power are merely the icing on the cake, and quite the sweet icing as pieces like these would suggest.