If it came down to owning just one watch, there’s no question that Seiko’s 6309-7040/49 is a strong contender. Still their top selling diver to date, it’s a tool watch so perfectly executed, it remains firmly at the top of our list. Balance, contrast, and contouring all neatly assembled into a finished product that is much greater than the sum of its parts. A bare bones beauty that more than proves that less is in fact, more. This example from March of ‘77 is a prime example. The matte black dial is perfect, and carries the Suwa “S” logo above the six o’clock marker. This signifies its earlier production, and that it was built and cased completely in Japan. The hour markers are free degradation or discoloration, and the luminous material has developed an even khaki patina. The hands show some light oxidation, and some color can be found at the edges of the luminous, but overall, they’ve aged beautifully. The bezel rotates with a firm click in either direction, and the insert has faded to an almost navy blue tint from UV exposure. It does show moderate wear, but all markings are still clear and visible. The case is unpolished, though most of the original brushed top finish has softened with age. The case back markings are clear and crisp, and only a couple of light tool marks are visible. Both the case back and crown screw down tightly with ample threading. The 6309A is keeping near perfect time post service, and ready for many more years of reliable service. We’ve paired it with a soft gray RAF NATO that’s both comfortable and versatile, and contrasts nicely against the dial. Completely original aside from a replacement crystal, it is a true Seiko icon, and a must have for any collector.

Clockwork Synergy Light Gray Double Layer Two-Piece RAF NATO (clockworksynergy.com

Serviced 7/10/19

Diameter- 44mm

Lugs- 22mm