It’s likely that no other reference better serves as the embodiment of “Seiko Diver” than the 300m Tuna. If for no other reason, its longevity makes it the clear front runner. For more than four decades, some evolution of the original 300m Pro Diver “Tuna Can” has continued to serve the Seiko faithful since it’s inception in 1978. Today’s “Marine Master” may have modern detailing and technological tweaks, but the lineage and identity is undeniable. It’s this instant recognition, regardless of age or era that makes a good tool watch great. Materials and technology evolve, but the overall design remains static. And when well executed, that design becomes timeless. Setting that tone for Seiko, was the 7549-7010. It wasn’t the first of the Tuna Can models, nor was it capable of reaching the same depths as its bigger brethren. It was however, easily the most versatile. The “Grandfather Tuna” was nothing if not capable, but it’s 600m depth rating meant strapping a veritable hockey puck to your wrist at more the 50mm in diameter. The “Golden Tuna” offered some reprieve housing a quartz movement, but that made little more than a single millimeter difference in case size. Though both were well received, they were purpose built without compromise, and that meant neither had any chance of sliding under a shirt cuff. The success of both enticed Seiko to develop the 300m variant. Using a more typical screw down case back design over a monocoque style lowered the depth rating, but also the overall height by a full millimeter (miles by watch standards). The new design also shaved 2mm off of the diameter, and a lower price point for consumers. Seiko had hit a sweet spot for the Tuna Can, and made an impression that has successfully lasted more than 40 years. Getting your hands on a modern 300 is certainly a worth while venture, but for many, owning the original is a goal worth setting. Good examples aren’t impossible to find, but this one from May of ‘81 is just phenomenal. The matte black dial is perfect with just a touch of creamy patina in the large luminous plots. The hands have retained their brightly polished finish, and the luminous within is spotless. The bezel action is buttery smooth, and the insert is practically perfect. The original shroud is secured by its original screws, and the factory sandblasted finish shows virtually no wear. The  crown and case back screw down securely with ample threading, and the crystal is the original domed hardlex. It’s unpolished and completely original, and post service with a new battery, it’s keeping perfect time. The original strap could not be salvaged, but we’ve paired it with an Uncle Seiko “Tire Tread” that’s supple, comfortable, and a flawless finish for this absolute stunner. If you’ve been waiting for the right 300m Tuna, this one will not disappoint. 

Uncle Seiko Repro “Tire Tread” Black Rubber Strap

Serviced 7/26/20

Diameter- 47mm

Lugs- 22mm