Doxa SUB 300T Aquamarine 840.10.241.10

The Doxa SUB 300T Aquamarine Ref. 840.10.241.10 is a modern professional dive watch that stays true to Doxa’s legendary tool-watch heritage while delivering serious, deep-sea capability. Reintroduced in 2019 as a tribute to the original 1969 SUB 300T Conquistador, this model features a 42.5 mm stainless steel case and Doxa’s unmistakable aquamarine (turquoise) dial, a vibrant colorway designed for underwater visibility and brand identity. The watch also includes Doxa’s signature unidirectional bezel with an integrated no-decompression dive scale, a hallmark feature that sets the brand apart from traditional dive watches.

Built as a true professional diver, the SUB 300T is rated to an impressive 1,200 m (120 ATM) of water resistance and includes a helium escape valve, making it suitable for saturation diving. Inside is a Swiss automatic movement with approximately 38 hours of power reserve, while a sapphire crystal with anti-reflective coating ensures durability and clarity. The watch is typically paired with Doxa’s iconic “beads of rice” stainless steel bracelet featuring a ratcheting wetsuit extension clasp, reinforcing its professional-grade functionality.

Reference: 840.10.241.10

Dated: 2026

Bracelet: Stainless steel bracelet "Beads of Rice", folding clasp with ratcheting wetsuit extension

Case: 42.5mm x 13.65mm Thickness x 44.50mm lug to lug - Stainless Steel

Lug Width: 20mm

Water Resistance: 120 ATM / 1,200 meters / 3,937 feet

Movement: Swiss Mechanical Movement - Automatic

Functions: HMS, Date, Helium Release Valve

Box and Papers: Box and Papers

Crystal: Sapphire

Bracelet size: 7.75”

New

DOXA, founded in 1889 by Georges Ducommun in Le Locle, Switzerland, has a rich history of watchmaking innovation. Initially gaining recognition for its pocket watches and dashboard clocks, DOXA's defining moment came in 1967 with the introduction of the SUB 300 dive watch. This groundbreaking timepiece, featuring an iconic orange dial, unique no-decompression bezel, and purpose-built design for recreational divers, quickly became a benchmark in the industry. Notably, in collaboration with Rolex and the introduction of the Sea-Dweller, DOXA co-developed the now-common helium escape valve concept, adding another feather in its cap as a true diver’s tool in its day. DOXA's reputation was further enhanced by its association with Jacques-Yves Cousteau and its frequent appearance in Clive Cussler's adventure novels.

Despite facing challenges during the quartz crisis, DOXA experienced a resurgence after its acquisition by the Jenny family in 1997. Today, the brand continues to honor its diving heritage while embracing modern watchmaking techniques. DOXA's journey from a small Swiss workshop to a globally recognized dive watch manufacturer demonstrates its enduring commitment to innovation, quality, and functionality. The brand's iconic designs, particularly the SUB series, remain popular among diving enthusiasts and watch collectors alike, cementing DOXA's place in horological history.