Owners Review : Don's Seiko Limited Edition 1000m 'Golden Tuna' S23626J1

Owners Review : Don's Seiko Limited Edition 1000m 'Golden Tuna' S23626J1

9 min read
Don Russell



Don Russell



Back in 1986 I bought Seiko dive watch, and that watch was the 7c46-7009 'Golden Tuna'.

I'd already been dabbling in this underwater malarkey for a while and had just sold my Heuer (long before TAG got involved) 980.023 1000m 'Deep Dive' to a friend. I dived in the Seiko for quite a few years until I bought my Rolex Sea-Dweller 16600. I'd already done more than 500 dives in the 'Tuna' at that point but needed to sell it in order to keep the bank manager happy, as he was now a relatively unenthusiastic part owner of a Sea-Dweller. The Sea-Dweller served me well for upwards of another 1500 dives or so.

Seiko Limited Edition 1000m 'Golden Tuna' S23626J1 - Credit WatchGecko

In 2018 Seiko released a 're-creation' as they called it, of the 1978 600m watch that was the forerunner to the 7c46-7009. This watch, the 7549-7009 I believe, was featured in two films, both on the wrist of the late Roger Moore; the first being 'North Sea Hijack' released in 1980 and the second being the Bond movie 'For Your Eyes Only' released in 1981. It took Seiko 7 years to develop the watch and it held around 20 patents. It was the first quartz powered saturation diving watch in the world and was helium safe without the need for a helium escape valve, thanks to the design of a special 'L'-shaped gasket under the crystal. The S23626J1 re-creation brought back memories of my earlier years and I managed to secure one through a friend. The edition was limited to 1978 (the year it was released) pieces and, as I understand it, only five were to be released directly into the UK, however, I heard that an additional two were released later that year.

Seiko Limited Edition 1000m 'Golden Tuna' S23626J1 - Credit WatchGecko 

Now, we all know how Seiko struggle to keep things aligned, such as bezel inserts, rehauts, seconds hands not hitting the mark and the suchlike, so, understandably, I was more than a little apprehensive about driving 100 miles to see a watch that looked like a five year old had thrown it together. When my friend brought out the watch for my inspection, he smiled and handed it to me. I sat in the corner of the shop with a mug of coffee, and he disappeared into the back, leaving me to it. To my surprise, and great joy I may add, everything lined-up absolutely perfectly; I took a mouthful of coffee and checked it again. I couldn't believe it! All that was left now was to try and negotiate some sort of discount. I gave him a shout and made my pitch, to be fair he did ease the price a little from the £2200 on the ticket and I paid the man.

All good?  

Almost! Quite a few have complained about the bezel being too tight to turn and having the original 7c46-7009 I knew exactly what the problem was. Inside the bezel nestles an 'O'-ring that makes the bezel feel more 'engineered', but unfortunately the 'O'-ring cannot retain the lubricant due to the case finish and this results in dry rubber. A couple of turns and it tends to lock, due to the dragging, and resultant distortion of the 'O'-ring. 15 minutes in the office and the job was done! A buttery-smooth bezel that'll bring a tingle to your fingertips. Another small modification that I felt was necessary involved changing the ceramic shroud's Titanium retaining screws. On the 7c46-7009 they were Titanium nitride stainless steel cross-recessed pan head screws, but on the re-creation they are Titanium semi-pan head hexagon drive socket screws that just looked wrong; these were removed and kept safe for the next owner. I ordered some A4 (marine grade stainless steel) button head socket screws that had been chemically 'blacked' and then waited patiently for their arrival. Fitting took no more than a few minutes and the rest, as they say, is history.

Seiko Limited Edition 1000m 'Golden Tuna' S23626J1 - Credit WatchGecko


The movement

The 7c46 movement is somewhat special; it was designed for the 'Tuna' and to this day, it only gets fitted to the 'Tuna' series, but what's so special about it?

Well, even today, it's regarded as the one of the most reliable, robust high quality quartz movements ever produced. It is equipped with low-drain electronic circuits that also enable the stepper drive system to deliver incredibly high torque, this, in turn, linked to a 7 jewel gear-train moves the 'Tuna's' massive cathedral hands with ease; all this results in a very acceptable battery life of 5 years. The magic doesn't end there!

The movement features a dual-rate trimmer system that allows synchronisation for superior accuracy; it also features what's termed an 'end of life' indicator, where the seconds hand moves in two-second increments while still keeping perfect time. Of course, this feature is commonplace today, but back then it was ground breaking! Today, as back then, it indicates that the watch battery is low and unsafe to dive with. Most of these units tend to run within -1/+1 second/month with this particular specimen performing even better. 

The name!

We can't really go on much further without covering the name. The vast majority of Seiko watches have acquired names by which they are lovingly referred. The 'Tuna' part refers to its shape, as it's like a can of tuna; some models are referred to as the 'Tuna can'. The 'Golden' part refers to the colour of the case. The original case was Titanium nitride coated Titanium (TiN) and was gold in colour, hence the term 'Golden Tuna'. Seiko have released many versions but the ones that don't have the Prospex logo are the most desirable, Prospex being short for 'Professional specification' and a relatively new addition; that said, they all come in a 'Prospex' box!

But what's it like to dive in?

It does exactly what it's supposed to do, and it does it extremely well! In fact, the Rolex Sea-Dweller has to move aside when serious underwater shenanigans are afoot. The 'Golden Tuna' is designed for one thing and it delivers 100% in every aspect of that area.

Seiko Limited Edition 1000m 'Golden Tuna' S23626J1 - Credit WatchGecko

I've dived extensively in both and it's definitely the 'Tuna' that wins out. The clarity is exceptional, the lume is legendary and it's incredibly well protected. Don't get me wrong, the Sea-Dweller is awesome, but under the water it has to be the 'Tuna'. Although my S23626J1 has been diving on quite a few occasions, it's also been on a good number of 'less moist' outings. Accepting that it's primarily a dive watch, it's an incredibly capable companion on outings where anything is likely; it's difficult to imagine a situation that the 'Tuna' couldn't handle!

After saying that, it doesn't handle sitting under a suit very well, and it does look a tad over-the-top when lounging in the jacuzzi, but that's about it. We couldn't end this bit without mentioning the lume! The S23626J1 is equipped with Seiko's 'LumiBrite' and it's incredible. My original 7c46-7009 was impressive, but had Seiko's previous offering, nevertheless, once charged it lasted throughout the night; however, this is on another level entirely, and the 'Tuna's' lume has become the accepted standard to which all other lume is compared. Once fully charged, the glow is so bright that you can actually read a book with it in a completely dark room!

Out of the water the 'Tuna' is just as impressive. I wear the watch for months at a time and it's not the monster that its size may suggest. Of course, I've been wearing these types of watches for close on 50 years and I rarely knock one. Could it be your only watch? For me, it was for a number of years! Is it exclusive? That's a difficult one, but I've seen many, many Sea-Dwellers during my travels, however, I've never seen anyone wearing another 'Golden Tuna', either above or below the waves. It's certainly a conversation starter if nothing else!

The case!

The case is manufactured in one piece from grade 2 Titanium and then it's Titanium nitride coated (TiN), although the coating does appear to be slightly different from that on my 7c46-7009. Everything goes in from the top and then the thick, sapphire crystal clamps it all together, held in place on top of the 'L' shaped rubber gasket with a 316L stainless steel castellated nut. The unit is then pressure tested in water to a depth of 1250m/125 bar (1000m + 25%).

These watches have been tested in the ocean to well over 3000m (9842ft.) without any ingress of water and keeping perfect time throughout. The spring-bars are massive 22mm Seiko 'fat-boys' and are likely to tear your arm off before letting go; there is no component on the watch that lets any other component down. The rubber strap supplied works exceptionally well and has a stainless steel tube inserted into the rubber for the spring-bars to pass through. This system increases the strength of the spring-bars substantially and ensures that any force applied is entirely in shear. With a normal rubber strap, the spring-bars pass through the rubber, and that can distort when a force is applied, this can bend the spring-bars and induces premature failure. The crown is threaded on the outside and mates with an internal thread in the case; this increases the diameter of the thread enormously over the normal design, and as such, its robustness.

Seiko Limited Edition 1000m 'Golden Tuna' S23626J1 - Credit WatchGecko



The 'Golden Tuna' is pretty much maintenance free in normal, everyday use. If used for its intended purpose the bezel mechanism will, from time to time, pick up bits of debris; this mechanism is easily cleaned by removing the four shroud retaining screws and lifting off the shroud. This ceramic shroud not only protects the watch but retains the bezel. Once removed, the bezel ring just lifts off, leaving the bezel ratchet mechanism. Once removed, clean the whole lot in warm, soapy water with a toothbrush and dry thoroughly. Rebuild with a small amount of silicon grease and re-fit the shroud. Battery change is incredibly simple if you have the correct tools.

Strap options

The supplied Seiko rubber strap is more than up to the job, but for diving I've found Zulu straps offer all sorts of advantages; however, some time ago WatchGecko gave me an OctoPod system to try and I'm completely sold on it! It gives me the additional security of passing through both spring-bars while offering completely adjustment-free wearing. It stretches over the dive suit and as the neoprene compresses with depth the OctoPod retracts, keeping the watch firmly in place; when ascending, the reverse is true. The OctoPod has remained on the 'Tuna' ever since and has completely transformed it for everyday use.

There's just something about the 'Golden Tuna'

I don't know what it is, and I can't explain it, but there's just something about the 'Golden Tuna' that oozes confidence. My original saw many escapades, both above and below the waves, thinking back, many of which make me cringe now; even so, the re-creation has not only brought back memories from an earlier time, it has also brought with it the urge to attempt some of the ridiculous things that I used to get up to! Back then we were both 'bullet-proof', unfortunately, I suspect that now it's only the 'Tuna'.

Current projects

Myself and Julie are currently working on a few things. The first, is diving for the treasure that was plundered by the infamous pirate Henry Avery; much of it lies in shallow water off the coast of Cornwall; this was filmed for Discovery Channel recently and will feature in an episode of 'Expedition Unknown' with Josh Gates later this year. Research suggests that some land based treasure may indeed exist, and new information in this area has suggested an alternate location to that currently being searched; this adventure is ongoing and is somewhat sea state dependent. At the other end of the British Isles, further research has revealed some interesting facts about the Jacobite gold from the 1745 uprising, and we hope to follow this up during the long summer days and short nights in the Highlands. That sounds lovely, and I've almost convinced myself!

In reality, it's Scotland and only two seasons exist, winter in the dark, and of course, winter in the light. We've been on this for a year or two now and it's a difficult area, so much so that other colleagues have given up the ghost, so to speak; it's certainly not a project for the faint of heart! Other stuff comes and goes and we sometimes get involved in the quest of others, such as the Avery project. Another action/adventure book may get finished this year but that's of secondary importance to actually getting out there!

What part will the 'Tuna' play? Well, whatever part it plays, I'm sure that it will be the star of the show. 

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Don Russell

About the Author: Don Russell

The timepiece of an adventurer serves not only as a trusted companion, but also as a portal to their inner self. My interest in watches goes back more than half a century; my reliance and passion more than half of that time. My hope is that I may inspire others to use their timepiece on their own adventures so that they may share a passion that has enriched my own life and given me so much enjoyment.

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