Doxa of Le Locle, founded 1889, had by the mid-1960s quietly established itself as a second-tier Swiss maker of robust, functional watches. In 1967 Doxa released what would become the most influential dive watch outside of Rolex and Blancpain: the Sub 300, designed around a set of deliberate innovations that addressed real underwater problems rather than marketing talking points. The most radical was the orange dial, the first in watchmaking, chosen because orange remains visible underwater at depth longer than white or black.
The Sub 300's tonneau case in steel, thick domed acrylic crystal, and unidirectional rotating bezel established the Doxa silhouette. The bezel was the second innovation: rather than a standard 0-60 minute count, it was calibrated with the US Navy no-decompression limits (e.g. 200 feet = 6 minutes at depth), allowing a diver to read directly how long they could stay at a given depth without incurring decompression stops. Water resistance was 300 metres (hence the name), making it one of the deepest-rated commercial dive watches of the 1960s.
The watch was adopted by Jacques Cousteau's Calypso dive team almost immediately after launch, and Cousteau himself wore a Sub 300 on-screen throughout the 1970s documentary series, in addition to donning one for countless dives with the Aqua-Lung crew. Cousteau also championed the design through US Divers (his company), which distributed the Sub 300 under the name "Aqua-Lung Professional" in the American market. Variants rapidly multiplied: the Sub 300T (1969) added a helium escape valve for saturation diving; the Sub 600T, 750T, and 1200T pushed depth ratings further; and the Searambler (silver dial), Sharkhunter (black dial), and Divingstar (yellow dial) expanded the colour palette.
Doxa entered a difficult period in the 1980s and 1990s as diving-watch demand softened, but the brand was revived in the 2000s under new ownership and in 2002 issued a limited-edition re-creation of the original 1967 Sub 300 that sold out immediately. Since then Doxa has remained a dedicated dive-watch brand, producing the Sub 200, Sub 300, Sub 600T, and 1200T in roughly their original silhouettes. Current Sub 300 Professional retail is around CHF 2,650, positioning it as one of the most distinctive affordable dive watches on the market. The orange-dial, tonneau-cased Sub 300 is today a recognised design classic on the same short list as the Submariner and Fifty Fathoms.
