The dive watch incorporated a solid stainless steel case of substantial proportions. At 45 mm in length and a width of 45mm, it went beyond the typical size of other watch cases being made at the time. This watch case was tested and proven to be water resistant to a depth of 300 meters (1000 feet) and would come to be named the DOXA SUB 300.
In an effort to have a highly visible dial, and therefore improve the watch’s overall visibility under water, it was agreed that a brightly colored dial might offer a better solution than the previous dive watch standard – black.
Several colors would be tested - red, yellow, turquoise and perhaps most importantly, orange. The testing was not undertaken at sea, but closer to home in Lake Neuchatel. As it happened, orange was thought to be the most “readable” dial color down to a depth of 30 feet owing to its bright, colorful appearance and thus it was obvious to the team that the first DOXA dive watch should have an orange dial. Remember – up to this time nobody had ever even conceived of something this radical – an orange dial?!
Urs and DOXA didn’t just stop with the orange dial and a water-resistant case though. They wanted to go even further. Perhaps one of the greatest hazards for divers is not knowing exactly how long they have been underwater as it relates to the maximum time that they can stay underwater. The US Navy was utilizing a no-decompression limit dive table.
This allowed the Navy’s divers to monitor the time and water depth while they dove. This seemed like such an obvious, useful function that Urs and DOXA started working on a rotating, unidirectional bezel that would utilize the Navy’s no-decompression dive table. Based on their successful adaptation of this design, Urs filed a patent for this bezel in April of 1968 (US patent No. 3505808). This bezel had two different scales on it and DOXA utilized orange to highlight the outer “depth” scale, and black to indicate the inner “minute” scale.
Another feature was born out of the team’s research – the now iconic “dwarf hour” hand. Urs and the team decided to use a minute hand that was substantially larger than the hour hand. This decision was so basic, so obvious, and yet nobody had thought of it before. The team knew, after all, that a diver would be more focused on measuring time in minutes not hours!
There were two final innovations which would make the use of the bracelet much easier. First, the bracelet incorporated a new type of flex-buckle. This ingenious expansion device attached to the buckle and easily adapted itself to the larger diameter of the wrist if the wearer was wearing a wetsuit, and then reduce its size to fit the wrist of the diver on dry land. Secondly, the original DOXA SUB bracelet had a unique “ratchet” mechanism built into the clasp. This allowed the bracelet to be sized without the need to remove links. Once the watch was placed on the wrist, and the clasp closed, the ratchet mechanism could be moved until the length of the bracelet corresponded to the wearer’s wrist size.