Last week article was a prequel, a necessary “mise-en-bouche” for the long-time and highly personal review of the Seiko Darth Tuna SBBN013 Prospex that you’re about to read. The Seiko Tuna is an important, yet iconic watch, a pioneer on its own – and a collection that boasted during its 40 years of life many innovations, with one and only goal in mind, satisfying the professional divers with an efficient and reliable instrument. It was important to learn first about the history of Seiko Tuna before moving to this review of the Seiko Darth Tuna SBBN013 Prospex. Now you’ll certainly ask yourself why a quartz watch came to be reviewed on Monochrome? Well, in one word, just be aware that it’s not every cheap quartz watch, it’s a Seiko Prospex. And if it has a quartz movement, it’s just to be even more reliable, secured and precise. After a review of the entry-level Seiko SKX007, it’s time now to move to serious watches, with the Darth Tuna SBBN013.
My Seiko Darth Tuna SBBN013 Prospex was bought from a good friend NIB and I decided to wear it for my summer vacations; the watch performed, as it should but let me provide firstly with the specs of the watch. The Seiko Darth Tuna SBBN013 is made from Titanium, Ceramics and Stainless Steel. The Shroud is ceramic, the bezel is S.S and all other elements of the watch are made from titanium. It has a monocoque construction (just like the first Seiko Tuna) and that means that there are two points of water ingress, either from the crown or from the crystal. It is waterproof to 1,000 meters and here we must mention that a recent experiment by Seiko Japan showed that the specific model strapped in the outside of an unmanned bathyscaphe stopped working at the depth of 3,284 meters; three times more than the indicated rating of the watch! The water pressure was so intense that the sapphire glass touched the hands so they stopped. The Tuna-can is antimagnetic as well and has the Quartz caliber 7C46.
Yeap! A quartz caliber. Please mecahnical-watch aficionados, read the following paragraph quoted by Poseidon Jim in the WUS forums.
“The 7C46 is a (Hi-Tech) multi jeweled movement with “Hi-Torque tolerances and High efficiency” built in over prior 7 series quartz movements, which enable the 7-jeweled gear train and pinions to motion & turn the hands in perfect sync to the energy-pulse, with much less kinetic effort via the electronic step motors that power them. Thus making for a highly accurate and efficient full size quartz machine to perform strongly with much less resistance. They also incorporate (dual-rate trimmers) which allow the watch to be perfectly synchronized for extreme accuracy, which aid in the longevity and add to there lifespan, while running well with in the stated accuracy specs. They also enjoy the added benefits of, Low-Drain electronics while providing High-Torque Power to the gear driven train and Over sized Hands for optimal efficiency & extended battery life. As an added plus, this caliber also incorporates the E.O.L. (End Of Life) Low battery warning feature, of the seconds hand ticking at 2 second intervals when the battery voltage is low, thus alerting the owner its time to replace the battery cell.
They also provide the Premium Benefits of being designed in a full expanded size, and are incorporated into the advanced Titanium alloy cases that house them, which are also very highly advanced designs on there own, with advanced shock protection built-in specifically for this movement. They also can be completely disassembled for cleaning & service many years down the road; that, together with the other quality design features therefore make this movement, the absolute highest quality advanced Professional quartz divers watch movement in the world.”
In my book, this is a perfect example of a caliber matching in perfect harmony with the watch and both serve their user perfectly. The 7C46 is not a mechanical caliber thus the main seconds hand has the one-second ticking and not the flowing movement of a mechanically driven watch. My romantic side thinks that this is just a battery watch. However the caliber is very exclusive and it was developed and chosen as the best option for a professional diving instrument. Seiko, in its instruction manual, gives a +/- 15 seconds per month deviation in accuracy. My own Seiko Darth Tuna SBBN013 Prospex was -1 second after 32 days. Furthermore, as we already mentioned, the life span of the battery is five years while many owners have reported that their battery hold even more than what Seiko estimates.
The Seiko Darth Tuna SBBN013 Prospex has a case diameter of 48mm, its height is 15,3mm and it weighs 114g. When just looking at the facts – the size, the height and the concentration of weight on the top of the wrist – all of this should imply a very uncomfortable wearing experience. However, in reality, it is not the case. The watch is big, however numbers are not always true. The two fundamental parameters giving us an uncomfortable wearing experience in any watch are mainly the weight and the lug-to-lug size. In that perspective, the Seiko Darth Tuna SBBN013 Prospex is very well proportioned. Let me explain. The watch has no lugs – actually they are hidden underneath the shroud and are placed well inside the case, so they don’t protrude. Therefore, the watch can be worn with superb comfort, due to a short lug-to-lug size. The weight is also relatively good if we consider the size of the watch; Titanium and ceramics do a great job, keeping the weight lower than expected. The only two things that might create an uncomfortable wearing experience are the height and the strap. Firstly, the Seiko Darth Tuna SBBN013 Prospex is not a Rolex Submariner. Due to its height, it can’t be worn underneath a shirt or a sweater. It does not even have the looks for that – it really is a diving instrument and not a desk diver. Secondly the strap provided by Seiko has a great quality but it is stiff. It also has a titanium buckle (DLC coated). From my experience after a few dives or extended periods in salt water, the strap started to become softer. However, due to my impatience, I replaced it with an excellent rubber strap made by the Italian company Bonetto Cinturini that is modeled after the original flat vent Seiko rubber strap.
As we already foretold, the case is made of titanium and the shroud from ceramics. The shroud’s purpose is to protect the watch from shocks and scratches – in or out of the water. From my experience, the shroud resists very well to shocks. No big scratches on my watch, no deteriorating either on the edges of the shroud. The shroud is secured by four hex screws. The modular design of the Seiko Darth Tuna SBBN013 Prospex allows for its user to remove the shroud with a tool in order to clean the bezel and the inner case of the watch. The problem here is that, after extended periods in salty-waters, salt residue, dirt and sand might stuck between the case and the shroud – and as a result, the bezel might become trickier to turn. This happened also on my own watch (even if it has always been rinsed with clear water after each diving sessions). The grippy and well-designed bezel turns with precision (it has 120 clicks) but I had to apply more force than before. So, on one hand the modularity of this watch permits its user to clean, or even to replace the shroud if damaged while on the other hand, for some, this unique construction detail is one of the negative aspects of the watch.
This Seiko Darth Tuna SBBN013 Prospex has a monocoque case. It’s adapts perfectly on the wrist – and that’s a good thing since this already thick watch sits as low as possible on the wrist. A monocoque design means that the watch is assembled from the dial (and not from the caseback, that is here fixed), like the mighty vintage Omega Ploprof. Service is not an easy task and because of this, service and battery change must be done by a Seiko official service center. The caseback – which is a superb piece on its own IMHO – is engraved with something truly unique: inscriptions for the battery change. A very neat feature which ads to the aura of this instrument IMHO. Also we must add that the Seiko Darth Tuna SBBN013 has no hollowed lugs like its smaller brothers or the high-end Emperor Tuna. Strap changes might be a little tricky with this one.
On the front side, we find a very fat sapphire crystal with a brown tinted AR coating on the inside. Only this model and the Emperor Tuna have sapphire crystal and not Hardlex (Seiko’s own proprietary crystal). High visibility in all situations is achieved since the AR coating really helps. Below the crystal we find the dial and the hands that are, in my personal opinion, fantastic. The dial is just like it should be on every serious tool diver watches. It’s extremely readable in a glance: large hands, precise edges, big markers. All are very well executed. The hour and minute hands are made of matt brushed titanium while the second’s hand is silvery and highly contrasting. Also the day/date compilation is very legible with a great size and placed wisely on the dial. The kanji font is also a great touch. Last but not least, this Seiko Darth Tuna SBBN013 has a massive crown, which screws with a very pleasant feeling.
Epilogue/ Overall Impression
The Tuna is a difficult watch to wear and even more difficult to properly comprehend. My first reaction when I saw a golden Tuna years back was to be in front of an hideous looking watch. After taking my time and starting to research other user experiences and seeing pictures, I really understood what this watch is all about. Personally I think that the Seiko Tuna (all editions) is one of the greatest diver tool watches of all time, and certainly it’s my favorite summer watch. It has a charisma that you rarely find, a unique character and surely it is a conversation starter. It is not another Sub clone. The Seiko Darth Tuna SBBN013 is constructed with professional standards and its quality can compete with far more expensive watches. Furthermore, it is very precise due to its quartz caliber (some won’t like it but, as a professional tool, quartz here makes sense). its stupendous character and the not-so-difficult wearability made me appreciate it even more. For its price point (around 2,200 Euros), the Seiko Darth Tuna SBBN013 is the best analogue quartz diver watch out there. I put mine through the test for a month doing scuba dives, Jet Ski and simple swimming sessions and the watch never ceased to amaze me. The only negative was that the feel of the bezel became harder to turn. This has happened to me in other watches, however with the Tuna you must take the bezel out in order to clean it.
Although I am fascinated by the Seiko Tuna’s history, character and pedigree but from my own positive experience, we must also note some downsides: the shroud, the quartz caliber, the monocoque design or its really professional look. Surely, it is not a Rolex Submariner or an Omega Seamaster. It is not a watch that you can wear in every situation. It is not mechanical. The Seiko Tuna is a professional grade diving instrument that tells time. It’s a very exclusive and very unique timepiece. You either love it or hate it, there is no middle ground. Seiko, at the start of the year made some stylistic changes in their Tuna model lineup with more models and revised material; thus, the Tuna still continues to dominate their divers watch catalog. It’s a legendary piece – period!
- For more information about the Tunas’ original development please check the Tokunaga archives on the SCWF forum. http://www.thewatchsite.com/29-tokunaga-archives/
- Also check information about the 7C46 caliber on WUS: http://forums.watchuseek.com/f21/what-makes-7c46-superior-movement-439547.html