The Rolex Oyster Cosmograph Daytona – Ref. 6263 and 6265

At the beginning of the 1970s, and until approximately the end of 1987, Rolex produced the two new chronograph references 6263 and 6265. In the continuous search to improve the waterproofing Rolex introduced various modifications differing from references 6262 and 6264, reintroducing the use of the screw-down push buttons and a large winding crown, as used on ref. 6240.

The Daytona Cosmograph references 6263 and 6265 differ from each other in the type of bezel: with black plastic insert and tachymeter printed in white for ref. 6263; in metal with engraved tachymeter for ref. 6265.

Characteristics of the Oyster Cosmograph Daytona watches:

Case: Oyster, screw-down push buttons, oyster Twinlock 700 series winding crown, calibrated metal bezel with black insert and tachymeter printed in white (ref. 6263), calibrated metal bezel (ref. 6265), domed plexiglass crystal (until approx. 1980).  The standard plexiglass crystal (from approx. 1980 to the end of production)

Dial: color contrast between dial and registers with ROLEX OYSTER COSMOGRAPH printing; DAYTONA in red above hour totalizer (only Stainless Steel models from the half of 1970s on) and also SUPERLATIVE CHRONOMETER OFFICIALLY CERTIFIED (only on gold models, not always present). Declared waterproofing of Cosmograph Daytona model is 50 meters (165 ft) approx. until the beginning of 1980s and 100 meters (330 ft) until the end of production.

[Source: Rolex Daytona History and Reference Guide : eBay Guides]