6239, Daytona, Double Swiss Underline, Steel

Double Swiss Underline. These three simple words mark one of the most significant Cosmograph made, a variant which many believe to be the very first Daytona ever made. In fact, it’s the variant from the ad where Rolex themselves first referred to this first model as the ‘Le Mans’, inspiring the name of the modern iteration. Collectors call it a Daytona because it began everything we think of as Daytona today. It is a 6239 with an external tachymetre, contrasting 'reverse panda’ subdials, and many small nuances that make this what it is: infinitely special, the very first Daytona made for one year only. 

This is a Rolex made in the details. The dial stands apart in many ways. The underline at 12—which gives the model its latter adjective—is believed by many to have been used to signify the transition toward tritium compounds from radium across Cosmographs, Submariners, GMT-Masters, and Explorers. All are highly collected. Underlines span from 1962 until ~1964, meaning that this 6239, introduced in 1963, was only produced for one year. Barely visible while cased, there is also a second Swiss signature outside the rehaut, the top of which just is visible. Its running seconds hand is flat-tipped, unlike the chronograph counters which are diamond-tipped. Later 6239 did away with this. The Double Swiss Underline (DSU) also features a small, white-tipped chronograph hand which left in latter variants. In addition, the hour hand almost touches the hour markers and is longer than most. DSU were made in white (true white, not silver) and this black reverse panda dial. All details are present and correct in this example.

Outside the dial, things are just and unusual and transitional. Its bezel is demarcated along the entire circumference, with an additional 275 mark which quickly disappeared after the DSU. This is the earliest Daytona bezel, also the very first time the scale had moved from the dial, like the 6238, to the bezel. Speaking of the 6238, all DSU feature 6238 inner caseback engravings, which might seem like it’s incorrect but is in fact the only correct caseback for this dial. On the Valoux 72B, you should also find the balance bridge engraved with ‘ROW’, Rolex’s US import mark. The US market was the very first to receive the Daytona, or, as it was called then, Le Mans. Additionally, there is a very specific serial range in which the DSU are found, all beginning with 923,XXX. This example is there. 

The DSU is amongst the rarest serial production Daytonas ever made. In addition, it is the very first Daytona. The DSU captures not only the monumental beginning of the Daytona, but lore of Le Mans. It caputures shifting production methods in the underline and collecting nuances like the caseback. This is, easily, the more beautiful Le Mans Daytona, even if few recognize it as such. All that sums to one of the most interesting, discreet, significant, and beautiful Cosmographs ever made: Genesis. 

This Double Swiss Underline 6239 presents in truly impressive condition. It is amongst the best examples currently known.

The case is a 9232XX serial, with extremely sharp and defined lugs. The surfaces all feature light wear without significant marks. Its case is very likely not ever polished. The caseback inner is signed 6238, correctly. It comes on a US market C&I expanding rivet bracelet stamped 66.

This dial present in comparably remarkable condition. Both Swiss signatures are correct and clear. All silver print is clear and unmarred. There are no hand strikes or damage of any kind. The tritium mix has aged to a yellow-orange tone, which fades off quickly under UV correctly. The small, white-tipped chronograph hand is present. The hour hand is long and correct. It retains its original flat-tip running seconds.

Sale includes original box & papers, however it should be noted that the guarantee slip is unfilled and blank as pictured. The calibre 72B is running well in specification, serviced prior to sale here. rs.

This example is modelled on an average-sized 7-inch wrist.