Doxa · Family: SUB 300T
The Doxa SUB 300T Professional 840.10.351.10 is a 42.5mm steel dive watch with an orange dial and 1,200 meters of water resistance (120 ATM), the 2019 reissue of the 1968 SUB 300T Conquistador — the first commercial dive watch with a helium valve — and a third Doxa reference clearly distinct from the SUB 200 and SUB 300 Caribbean already in Cazador thanks to its greater certified depth. It runs a Swiss automatic caliber with 38 hours of power reserve. Cazador has no verified price observations (n=0) for this reference as of today.
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Insufficient data: 0 price observations (PricePoints) recorded as of July 25, 2026. Cazador does not estimate or infer a range without sourced market data.
Doxa was founded in 1889 in Le Locle, Switzerland. In 1967 it launched the SUB 300, one of the first dive watches with a high-visibility orange dial and a bezel with an integrated decompression calculator, developed with diver and explorer Jacques Cousteau and his team.
A year later, in 1968, the brand introduced the SUB 300T Conquistador, the first commercial dive watch fitted with a helium release valve, built to handle the decompression needs of divers working in saturation diving bells at great depth.
In 2019, Doxa revived that model with the current SUB 300T, which keeps the 'Professional' orange dial, the feet-graduated bezel with decompression calculator, and the helium valve of the original, while raising certified water resistance to 1,200 meters (120 ATM), well above the 300 meters of the SUB 200 Professional and SUB 300 Caribbean references already in Cazador's catalog.
The 840.10.351.10 runs a Swiss automatic movement with 38 hours of power reserve, in a 42.5mm, 13.65mm-thick 316L steel case, available with a 'Beads of Rice' steel bracelet or FKM rubber strap. [UNVERIFIED: we do not confirm the exact base caliber of this movement in the official spec sheet consulted]. This is the third Doxa reference we're adding to Cazador's catalog.
Cazador has no verified price observations for this reference (0 PricePoints recorded as of July 2026). We do not publish estimates without our own sourced market data.
It was the first commercial dive watch fitted with a helium release valve, built for the decompression needs of divers working in saturation diving bells.
The SUB 300T is certified to 1,200 meters and includes a helium valve; the SUB 200 and SUB 300 Caribbean references are certified to 300 meters without a helium valve.
Doxa introduced the high-visibility orange dial on the 1967 SUB 300, developed with Jacques Cousteau's team to improve underwater legibility.
It releases helium gas that builds up inside the watch during the decompression of divers working in deep saturation dives, preventing damage to the crystal.
38 hours, according to the brand's official spec sheet.