To celebrate the 55th anniversary of its first diver's watch, Seiko offers three revisitations of the most important models from the first decade of its production. Seiko's (and Japan's) very first diver's watch, unveiled precisely 55 years ago, featured an automatic movement and water resistance to 150 metres and proved to be reliable through its use by members of the Japanese Antarctic research expedition from 1966 to 1969. In 1968, the first Seiko diver's watch was created that was water-resistant to 300 metres and had an automatic movement with 10 oscillations. It was successfully used by the first Japanese to climb Mount Everest, but this achievement was, at least in part, eclipsed by the receipt, in the same year, of a letter from a professional diver stating that no diver's watch yet created could withstand the conditions that were his daily reality in saturation diving. The Seiko team realised that a technical change was needed to create a diver's watch that could truly be called 'professional'. Thus, in 1975 the company produced a diver's watch to 600 metres (nicknamed 'Tuna') that exceeded the limits of any diver's watch in history. True to the original design, all three watches presented today by Seiko are absolutely up-to-date in their specifications and execution. The greatest advancement lies in the quality of the stainless steel used in the construction of the cases, namely 'Ever-Brilliant Steel', a type of steel more resistant to corrosion than that used in most high-end watches today. The 1965 and 1968 revisions are powered by the high-frequency 8L55 movement while the 1975 one mounts the calibre 8L35, both developed and assembled expressly for diving watches in the Shizukuishi Watch Studio. All three are fitted with sapphire crystal. The 1975 version has an increased antimagnetic resistance of 40,000 a/m thanks to the dial made of pure iron. All three models are produced in a limited edition of 1,100 pieces. In addition to the three limited edition models, the first Seiko diver's watch will also be celebrated with a modern reinterpretation made entirely of stainless steel. It features the same special 55th anniversary blue-grey dial as the three reinterpretations and comes with both a stainless steel bracelet and a silicon strap. It is powered by Calibre 6R35, which guarantees a 70-hour power reserve. It will be available in a limited edition of 5,500 pieces.
