This is a Seiko Hi-Beat Professional 300m Dive Watch, reference 6159-7001, first introduced in 1968. Also known as the ``Grand Seiko Diver'', the 6159-7001 was a second 300m model from Seiko and was equipped with a Seiko Hi-Beat 6159A automatic movement and elasped time bezel (the first 300m model, introduced in 1967, had a count-down bezel and an inferior automatic movement that could not be manually wound). The calibre 6159A was 36000 bph, manually windable, and featured quick-set date and hacking capability. Movement was enclosed in a stainless steel ``waterproof'' one-piece case and, hence, was accessed from the front, by removing the screw-down crystal.

Luminescent markers on the hands and hour indices were trimmed in gold. The dial was also waterproof and had the following inscription:

Seiko
Automatic
Hi-Beat
Professional
Water 300 Resist
Japan 6159-7001

The gold Seiko logo was not an inscription but rather a seperate attachment, like the gold trimming used on the hour indices. The one-piece case had slanted edges on either side of the caseback which made its huge presence on the wrist extremely comfortable. Screw-down crown was protected by the the ``shoulder-less'' case in such a modest way that it looked as though it was unprotected.

Although Seiko 300m dive watch was loved by many scuba divers because of its depth rating, unmatched design and comfortability, the retail price of 30,000 Yen in 1968 was simply too expensive -- at that price, many divers instead opted for a Rolex Submariner even if Rolex was more expensive than Seiko 300m. The production of 300m dive watch was reported to have ceased in early 1970s. In 2000, Seiko reissued a limited edition of 6159 300m dive watch as part of their historical collection with a slightly different calibre and dial inscriptions. They also sold a contemporary version of the 6159 under the name ``Seiko MarineMaster''. The watch I have reviewed here was the original model, first sold in 1968.