Introduced in 1965, Seiko's innovative diver's watch has been chosen by divers and adventurers globally. Seiko's diving watch has become a global standard as a result 50 years of innovation. Everything started with a letter from a professional diver in Hiroshima prefecture of Japan. The diver explained that no watch was robust enough to withstand the stresses and strains he experienced when using a diving capsule and saturation diving techniques in depths greater than 300m. Answering this request, Seiko's engineers set to work and after years of research development, the world's first titanium cased diver's watch, the Professional Diver's 600m, was created.