Seiko Prospex Spring Drive Tuna SBDB008

Seiko Prospex Spring Drive Tuna SBDB008

by Matthew Boston
$1,000 - 9,999, Seiko

One of Seikos best known sports lines the Prospex feature outer “shroud” cases that are attached to an inner case using four screws which lead to them being nicknamed “Tuna” due to the resemblance to a tuna can. The “Tuna” dive watches deserve higher recognition but are less well known due to them being ‘Japan only’ models.

This latest limited edition pays tribute to the original diver design Seiko introduced in 1975. The original shrouded “Tuna Can” was an automatic 600m diver which used a titanium shroud because of its light weight, its corrosion and abrasion resistance as well as offering good shock resistance to the inner case. Seiko introduced the 1st quartz version of the 600m diver three years later and this had similar black and gold accents. Its appparent that this edition combines design elements from those two early models.

Since the first one , the automatic Professional 600 m ref. 6159-70 10 designed by Seiko engineer Ikuo Tokunaga and released in 1975 for saturation divers there have been many variations with both mechanical and quartz movements however this latest version, the Seiko Prospex Spring Drive Tuna SBDB008 is the first to be fitted with the high end Spring Drive movement.

That makes this an interesting fusion of new and old, bringing together the classic Tuna design pedigree together with the modern technical virtuosity of the Spring Drive movement.

Seiko Prospex Spring Drive Tuna SBDB008 – Case and Movement

Both the case and the shroud of this latest incarnation of the Tuna are constructed from titanium unlike the so called “Emperor Tuna” (SBDX011) which comes with a ceramic shroud. The most notable aspect apart from the inclusion of a Spring Drive movement in this model is the gold-coated bezel, crown and shroud screws. From 12:00-3:00 and 6:00-9:00 gold highlight accents on the bezel are exposed allowing for easy grip, but also giving a nice detail. The gold plated crown at 4:00 looks great and also allows for comfort and security.

Seiko Prospex Spring Drive Tuna SBDB008

Seiko Prospex Spring Drive Tuna SBDB008

Despite similarities to other Tuna models there are various exceptions that distinguish the SBDB008 model. The outer case or “shroud” is most apparent .The shroud was developed by Seiko as a way of protecting the inner case from impacts that could occur when using the watch during dives, however despite its practical purpose the shroud has become a distinct design feature giving it the unique identifying look of the “Tuna”. Unlike its larger sibling the 1000m SBDX011 or “Emperor Tuna ” which has a ceramic shroud the SBDB008 has a DLC coated titanium shroud which is in a dark grey. This model is also distinct from other models in that it has a screw back for accessing the movement instead of being a one piece case like most other Tuna`s.

Another key difference with this model is the high level of finishing apparent on the case. Particularly noticeable on the shroud which has at the top a polished bevel and a fine vertical brushed finish on the side.

In terms of similarities this model, like other “Tuna” variants has no lugs, the strap being directly attached to the shroud. This helps make the “Tuna” comfortable to wear despite its typically considerable size, in this case being 50.5 mm in diameter and 16.2mm in height.

The SBDB008, like other Tuna dive watches can be used for saturation diving. It doesnt feature a helium release valve but the L-shaped gaskets and special case construction prevent helium from entering the case therefore negate the need for this feature.

Seiko Prospex Spring Drive Tuna SBDB008

Seiko Prospex Spring Drive Tuna SBDB008

Inside the SBDB008 case, for the first time in a “Tuna” dive watch is the Spring Drive caliber 5R65 which has 30 jewels, the mainspring driven, quartz regulated Spring Drive movement offers the best of both worlds and has a power reserve of up to 72 hours and is rated at +-15s/month.

Considering its size the total weight of this piece is only 118g thanks to its use of titanium. It comes on a polyurethane strap which was also used on the 1975 original . A PU strap is used because of its elasticity which helps it compensate for changes in wrist size at different pressures.

Seiko Prospex Spring Drive Tuna SBDB008 – Dial

Apart from the hour, minutes and seconds a power reserve indicator is shown on the dial -as is found on all Seiko watches using the Spring Drive movement- and at the 4.30 position the date is displayed.
The SBDB008 uses Seiko’s in house developed Lumibrite and is applied very thickly on each index, the hour and minute hands, the end of the second hand, and the 60 minute mark on the bezel. In matching gold-colored font the text “Marinemaster Spring Drive Professional 600m” is shown above 6 o’clock, this is a first for shrouded divers.

Seiko Prospex Spring Drive Tuna SBDB008 – Conclusion and Pricing

Its a pity that this impressive new “Tuna” dive watch from Seiko is limited to just 300 and sadly is also a Japan-only release once again, however Im sure if you are really desperate to get hold of one “where theres a will theres a way” as they say. The retail price for the Seiko Prospex Spring Drive Tuna Can SBDB008 is $4,500

More resources about the Seiko Prospex Diving Spring Time Tuna SBDB008 available on ArizonaFinetime (Hands-On).

    Author Bio

    Articles by Matthew Boston


    Matthew Boston has worked in the computer graphics industry for 17 years in various parts of the world, currently residing back home in the UK. His interest in watches was first piqued as a youngster when he was fascinated by a Seiko digital watch he received. He's also founder of UniqueWatchGuide which is dedicated to sharing the news about timepieces that are unusual, unconventional and more often than not unobtainable.