Tudor Oysterdate 9430/0 First Series

This Tudor "Big Block" Chronograph Ref. 9430/0 from the 1970s is a timepiece of rare beauty and historical significance. It is not only part of the highly sought-after first series of this model, but also an example whose sub-dials have developed a fascinating tropical patina over the decades – a unique aging characteristic that lends the watch its unmistakable allure.

In 1976, TUDOR introduced the third generation of chronographs, marking a decisive innovation: for the first time, the brand equipped them with an automatic movement, the renowned Valjoux 7750. To accommodate the rotor, the case height increased – and soon the distinctive chronograph earned the nickname "Big Block" among collectors.

The very first versions of the Prince Oysterdate, like this one, proudly showed the inscription "CHRONO TIME". In later series, this was changed to "AUTOMATIC-CHRONO TIME". As such, this early example indisputably belongs to the rarest and most desirable variants of the Big Block line.

The dial is particularly impressive: once bright, the sub-dials have gradually acquired a warm, authentic tropical hue that blends the sporty character with a touch of vintage charm. Combined with the stainless steel case, the tachymeter bezel, and the characteristic date display with magnifier, the result is a watch that convinces both technically and aesthetically.

Inside, the Valjoux 7750 ensures reliability while also offering practical features such as a quick-set date function – a technical advancement that made the watch just as practical in its day as it remains today.

All in all, this Tudor Big Block unites sporty presence, historical relevance and a patina of irretrievable beauty. A chronograph that makes collectors hearts beat faster and radiates pure vintage fascination on the wrist.

Condition Report
Dial: flawlessly preserved matte black surface – beautifully aged sub-dials with natural patina – signed "Tudor Chrono Time T Swiss T".

Case: Big Block stainless steel case – excellent condition – light signs of wear – sharp edges – intact engraving on the back: "Original Oyster Case By Rolex Geneva" – correct reference number engraving inside the caseback.

Movement: automatic Valjoux 7750 caliber – timing machine results: rate deviation: -15s/day, amplitude: 225, beat error: 0.1.

Bracelet: original Rolex Oyster stainless steel bracelet – reference 78360 – light signs of wear – clasp code: V2 (1996) – end links 605 – adjustable length between 18.9 and 20.9 cm.

Serial number: 872xxx

Int.Exe.: 40220