Dive watches distinguish themselves by size, being typically bigger and bulkier than other watch categories. And also function, usually coming equipped with a rotating bezel (the ring around the crystal, used to record elapsed time/ oxygen), a helium escape valve and a screw-down crown. Dive watches as we know them now date back to the early Fifties and are marketed today on brand history and by association with the sea. Rolex’s Submariner, Omega’s Seamaster and Breitling’s Superocean are some of the most well-known examples, and remain among the best-selling and best-reviewed lines. Rolex can take the credit for popularising the style though, pioneering advances in in water-resistance with the first ‘Hermetic’ watch in 1924 and then its ‘Oyster’ watch in 1926.