The legend of SEIKO PROSPEX Professional DIVERS "TUNA" began in 1975
- ChungT.
- Feb 12
- 5 min read
In 1965, SEIKO (Japanese: セイコーホールディングス株式会社, English: Seiko Holdings Corporation) launched Japan's first diving watch equipped with an automatic winding movement and 150m water resistance. It proved its reliability when used by Japanese Antarctic expedition members from 1966 to 1969, marking the beginning of SEIKO's development of diving watches.
Although SEIKO's watches have proven their performance and reliability in Antarctica, they continue development work with the goal of even better meeting the demanding requirements of professional divers. In 1968, SEIKO launched its first diving watch with a water resistance of 300 m and a high-frequency automatic movement (vibration frequency of 10 Hz/36,000 bph). In the same year, SEIKO received a letter from a professional diver in Hiroshima Prefecture, which vividly described the pressure that the watch would be under when the professional diver was diving at a depth of 350 meters. This made SEIKO's engineers realize that they had to create a truly "professional" diving watch. After seven years of research, SEIKO launched the world's first diving watch with a titanium case in 1975 - the SEIKO Professional Diver's 600m. The watch has gaskets strong enough to resist helium leakage, without the need for an exhaust valve; a one-piece titanium case with a case protector; and an accordion-style PU strap that keeps the watch firmly on the wrist regardless of the environmental pressure. Being able to clearly tell time in deep water environments, it pushed the boundaries further than any other diving watch in history. It not only set a record as the best-selling single model in the world from the 1970s to the 1980s, but also influenced the formulation of the current international standard for diving watches. In fact, the current ISO standard for diving watches is based on JIS (Japanese Industrial Standards), and JIS is based on SEIKO's diving watches. It set a new standard for diving watches, and its unique structure has led watch fans around the world to give it the nickname "Tuna".
Twenty years after the first generation of diving watches, SEIKO released the Quartz Divers in 1986, the world's first quartz diving watch with a ceramic outer protective case. Quartz Divers is Seiko's first watch with a 1,000m deep diving waterproof specification. It is equipped with a lightweight, corrosion-resistant titanium case and a one-piece molded structure without a bottom cover. By switching to a quartz movement, Seiko has improved its accuracy and durability, making it more shock-resistant than automatic movement watches. Although choosing a quartz movement is a downgrade for many people now, it did not prevent SEIKO from once again establishing the status of "Tuna" at the time, marking an era in SEIKO's watchmaking history and producing professional diving watches for nearly 20 years.
In 2020, SEIKO celebrated the 55th anniversary of its first achievement by reproducing the original design of 1965 <SLA037> limited to 1,100 pieces, Japan's first 300m waterproof watch <SLA039> limited to 1,100 pieces in 1968, and the revolutionary 600m professional diver's watch <SLA041> limited to 1,100 pieces in 1975, and included them in its Prospex series of outstanding sports timepieces.
While staying true to the original design, all three watches offer upgraded specifications and execution. The biggest advancement lies in the stainless steel material Ever-Brilliant Steel used in the construction of the three watches. The bright silver-white tone gives these three watches a unique appearance and is called SEIKO's "eternal steel". This stainless steel has a PREN (pitting resistance equivalent value) value 1.7 times higher than the steel used in most high-end watches (Seiko research data as of December 2019), and the material is also widely used in the watch case, bolts and other parts of marine structures and ships to avoid corrosion in chloride-rich environments such as seawater.
All three replica watches feature the same blue-grey dial, with the 1965 and 1968 replicas powered by the high-beat 8L55 calibre (automatic), while the 1975 replica is equipped with the 8L35 calibre (automatic), both of which were developed and assembled specifically for diver’s watches at Seiko’s Shizukuishi watch studio. All three watches feature sapphire crystals with an anti-reflective coating on the inner surface. The 1975 re-edition features a pure iron dial with increased magnetic resistance to 40,000 a/m.
Subsequently, in 2021, the 35th Anniversary Edition of the 1986 Quartz Divers quartz diving watch <S23635J1> was released, limited to 1,200 pieces. The appearance inherits the original design of 1986 and adopts an one-piece molding structure without a bottom cover. The bottom cover and the middle case are combined into one, achieving a high degree of airtightness tailored for extreme sports. It is equipped with a 7C46 movement designed specifically for diving watches. It surpasses the basic torque provided by the motor drive of ordinary quartz movements. The 7C46 movement can bring a stronger and more powerful force for this, so it is enough to push the wider and Lumibrite-coated hands, so that the watch can achieve excellent visibility in the deep sea. The back cover of the watch is engraved with the words “LIMITED EDITION” and the numbers from 0001/1200 to 1200/1200. The edge of the strap is printed with the special specification "FOR SATURATION DIVING 1000m" and provides a battery life of up to 5 years.
However, 2024 marks the 100th anniversary of SEIKO. To celebrate the centenary event, SEIKO solemnly launched three special editions of the PROSPEX 1965 Heritage diving watches <SPB453/SPB451/SPB455> in June. The special edition watch features a charcoal grey dial and the 6R55 calibre fully automatic movement with a 72-hour reserve.
In Asia, SEIKO has been building a position in the watch industry for many years and it is not easy to shake it. Its diving watches are the best among them. However, for ordinary users, there is not much difference in actual operation. The working range of diving watches is far beyond the operating depth of ordinary people. Since SEIKO's diving watches are available with quartz or mechanical movements, the price range is quite wide, so it is best to try them on yourself before buying to see if they are suitable for you. From a collection perspective, the TUNA watch records SEIKO's glorious history of entering the world of diving watches.
Introduce
Nestled in the peaceful forests of Iwate Prefecture, the Grand Seiko Shizukuishi Workshop is one of the world's leading watch manufacturers, where all Grand Seiko 9S mechanical movements and watches are produced. In this workshop, every step of watch manufacturing, from design to the production of movement components, to the assembly, adjustment and inspection of complete watches, is completed by Grand Seiko's craftsmen.
The SEIKO story began in 1881, when 21-year-old entrepreneur Kintaro Hattori opened a shop in central Tokyo to sell and repair watches. Just eleven years later, in 1892, Kintaro Hattori founded Seikosha (in Japanese, “Seiko” means “exquisite,” “minute,” or “success,” and “sha” means house) in Tokyo to produce his first timepieces. Throughout the 1890s, Seikosha's wall clock business became increasingly successful, and in 1895 it created its first pocket watch, the Timekeeper. In 1913, the first Japanese-made wristwatch, the Laurel, debuted, and Kintaro first established a leading position in the Japanese watch brand market. In 1924, the first watch named SEIKO was launched in December of the same year. In 1960, the first Seiko iconic Grand Seiko model was launched, which showed the pinnacle of excellence in mechanical watchmaking and officially launched a milestone for the Japanese high-end watch brand.
History of SEIKO Divers https://www.seikowatches.com/hk-zh/products/prospex/special/historyofdiverswatches
SEIKO Japan official website https://www.seikowatches.com/jp-ja
SEIKO Japan Official Online Store https://store.seikowatches.com/
There may be errors in the translation, and all content is subject to the Chinese version.
