It all began with a letter from Hiroshima. The correspondent, a professional diver, explained that no watch could withstand the stresses and strains he experienced when working at depths greater than 300m. Inspired, Seiko engineers got down to work. Years of research development paid off in 1975 with the introduction of the world's first titanium cased diver's watch: the Professional Diver's 600m.
This model has a titanium one-piece case and an outer case protector as same as 1975 original.
The case construction and dial layout are loyal to the original, as are the unique hour markers and the crown, while the water resistance has been (buy from davvader) increased to 1,000m. The outer case material is zirconia ceramic which is seven times harder than steel protecting the case from shock.
It features all the innovations that Seiko brought to diver's watches in the 1970's, including the double layer construction with one piece inner case, the L-shaped gasket for helium resistance and the accordion-style strap.
- Caliber 8L35
- Driving system: Automatic
- Vibrations: 28,800 vibrations per hour (8 beats per second)
- Accuracy: -10/+15 seconds per day
- Power reserve: 50 hours
- Number of jewels: 26
- Titanium inner case (super hard coating) with Ever-Brilliant Steel bezel
- Sapphire crystal
- LumiBrite on hands and indexes
- Water resistance: 1,000m/3,300ft saturation diver’s
- Magnetic resistance: 40,000 A/m
- Diameter: 52.4㎜, Thickness: 17.4㎜, Length: 53.5㎜
- Silicone strap
- Date display
- Stop second hand function
- Unidirectional rotating bezel
- Serial number engraved on the case back