Seiko Tuna


The SeikoTuna

This Seiko Dive watch, SBBN007 got its nickname due to its similarity to a can of Tuna (when viewed from the side.)

The Seiko Tuna is part of the Prospex line of Seiko Dive watches which are a range of upscale watches from Seiko, and the overall build quality and specifications are a cut above the Monster and other 7S26 powered divers.

The Tuna is even bigger than the “Monster” at 48mm not including the crown and is 14mm thick. Ticking inside its stainless steel hulk is a 7C46 quartz movement made specifically for this model and extremely accurate. The battery is rated to last 5 years and theres a small engraved mark which signifies which year the battery should be changed which is a neat idea.


The crystal is heavily domed adding a nice stylistic effect to the watch and further enhancing its bold impression, this exaggerated doming pushes it beyond the protection of the bezel so care needs to be taken to avoid scratching. The Tuna uses Seiko’s propriety Hardlex crystal material which is more shatterproof than sapphire but not as scratch resistant.

Like the monster the Seiko Tuna uses Seiko’s Lumibrite, and although not quite as bright as the Monster it still has a good glow to it.

Seiko Tuna Basic Specifications:

Water resistance: 300m
Size: 48mm
Caliber : 7C46 Quartz
Price: $500 still available some places in Japan and secondhand in US/EU (New model SBBN017 approx $800 depending on exchange rate)

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