There exist numerous vintage Seiko divers popular with "Seikoholics" collectors, but none more so than the venerable 6309 series - like this 1979 Seiko 6309-7040 automatic diver here.
The 6309 series of diving watches was the third generation of Seiko’s recreational/professional divers. The 6309 line replaced the 6105 in 1976 and was produced until 1988, when Seiko replaced it with the 7002 diver. 6309’s were a successful effort by Seiko to improve the 6105 movement, which allowed for greater lifespan, robustness, and ease of maintenance.
The 6309 line was produced in two separate case variations: an earlier cushion case, popularly known as the “turtle” for the appearance of its cushion case, which was produced between 1976-88 (making the 6309 on offer here one of the first produced by Seiko), and a slimmer case version from 1982-88. The 6309 was popular with the U.S. military, akin to the Seiko model it replaced, the 6105 - its (much more expensive) forefather - and quickly became the staple of the working diver.
The 7049 was designated for the North American market, and the 7040 was for the Japanese Domestic Market (JDM) and the rest of the world.
This Seiko 6309 diver comes with its original rubber strap, velcro "NASA" strap, Pelican travel case, and springbar tool.
1979 Seiko 6309-7040 Automatic Dive Watch
DIAL: Black Seiko dial, with subtle fading of the red dial font to a reddish yellow/green, normal for these 6309s. Roman/English day variants and date functions at the 3 o'clock position work as designed, with a deep bevel on the day/date window (a correct indicator of an earlier model 6309). Hands evince patina.
BEZEL: Bi-directional and ratchets with click. Bezel insert shows slight wear, impressive given the age of the watch - these inserts are normally first to be heavily damaged when these diver's were used as designed, ie: hard.
CASE: Hefty 44mm (w/o crown, 44.5mm with) x 45mm stainless steel cushion case, with sharp case lines. Matching caseback - the Seiko wave emblem is clear and defined, with the "frost" remaining on it.
CRYSTAL: Hardlex crystal, no scratches or imperfections.
BAND: This 6309 comes with its original rubber Seiko-signed strap; rubber remains pliable with no cracks. It also comes with a dark brown/green velcro ZULU strap, akin to those worn by NASA astronauts over their suits, albeit shorter.
MOVEMENT: 6300-series Seiko automatic movement, 17 jewels, manufactured in April 1979.
CROWN: Screw-down unsigned stainless-steel crown, tight as designed.