The SBBN027 - Yellow Fin Tuna?

This is a different entry into the Seiko Tuna family.  The Yellow Tuna is has a quartz movement.  It is unlike most of the more recent tuna models that we have seen because of this movement.  A quartz movement in a tuna isn't entirely new, they have released quartz models around the same time as they would do an automatic movement.  What makes this interesting is not only the movement, but the fact that it is a Seiko Marine Master, the high-end Seiko dive line.  The Seiko Tuna is one of the most iconic wristwatches today.  The tuna style watch took over 7 years to design.  They started this long design process in 1968 when a saturation diver complained that his Seiko watch couldn't take the abuse.  Seiko had just gotten into the dive market three years before.  The original Seiko Tuna was released in 1975 by a design team lead my Ikuo Tokunaga.  That watch had a lot going for it, so much so that Seiko was awarded 20 patents.  Later, in 1978, Seiko developed the first saturation dive quartz watch, another Tuna, affectionately called the Golden Tuna.  So, as you can see there have been other quartz tunas.  The SBBN027 is in many ways a tribute to that iconic watch.

Depth and the Seiko Tuna Can Design

The "Tuna Can" design which helps against the pressure that diving deep causes.  When the Seiko Tuna was designed they must have gotten something right.  The Seiko Tuna is an essential dive watch from the special casing to the first vent style dive band.  An design that helps the diver with the expanding and shrinking of rubber at different depths.  A band that is in use on almost all "rubber" silicone dive bands for Seiko.  The casing was so revolutionary and so perfect, that Seiko has seen no reason to have any major changes.  

What is so Special About a Quartz Movement

The movement of the SBBN027 is a quartz movement.  While that might sound simple and have you wonder why would a Marine Master have a quartz movement, it is no ordinary quartz movement.  This is a 7C46 quartz movement that is custom built to handle great depths.  This watch is tested at 1,000 M.  The movement is a multi-jeweled movement with extremely "Hi-Torque tolerance and High efficiency" built in over prior 7 series quartz movements, which use 7-jeweled gear-train and pinions to motion and turn the hands.  This creates a perfect sync to the energy-pulse.  It is a hi-tech movement with all metal components that fill the entire case back.  The 7C46 is also specially designed to be shock resistance and take the abuse of a professional diver.  This all means that the SBBN027 movement is highly accurate low energy consumption movement.

The SBBN027

The Yellow Tuna is a sporty watch.  It is cool for being so different.  It is a watch that doesn't try to be something for everyone.  No, it is what it is, and that is a professional dive watch.  I can easily picture this watch among other dive gear like regulators, tanks and gauges.  The case is built in a one piece casting, the "shroud" protects the watch from pressure and abuse from diving.  The shroud is made of a tough black ceramic.  It is a watch for those who go on adventures.  It is a watch for someone who truly lives and wants their watch not to be some crappy digital screen that can't take any abuse.  No, instead they want a work of tradition and engineering, something that can take the abuse.

The Quartz Yellow Tuna SBBN027

First thing about the this Tuna Marine Master watch is that you have to realize it is a large watch, the good thing is that it is smaller than the mechanical tuna watches.  It is smaller, but it is still a solid 49.5 mm watch case.  Also the watch is 15.5 mm thick.  The watch has an amazing depth rating of 1000 meters

Seiko Marine Master: SBBN027

Drive System: Battery-Powered Quartz
Caliber: 7C46
Case Material: Titanium w/ Diashield and Ceramics
Band Material: Silicon band
Glass material: Sapphire
Lumi Brite: Yes (needle index)
Accuracy: ± 15 seconds per month difference
WaterResistance: 1000m for saturation diving
Battery Life: About 5 years
Antimagnetic: Yes
Size: Vertical 49.4mm × 49.4mm × thickness 5.3mm
Weight: 125g
Other Features: Screw Back - Rotating bezel