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In 1975, A saturation diver from Kure City in the Hiroshima prefecture of Japan sent Seiko a complaint regarding the reliability of it’s existing line of professional dive watches. The complaint exposed some notable flaws in it’s existing design, most notably their susceptability to the absorption of helium gas, a component of the air mixture that saturation divers were enveloped in.
In response, Seiko’s engineers (led by Ikuo Tokunga), set out to make the perfect dive watch for professional saturation divers. Nicknamed the “Tuna” because of it’s cylindrical slab of lugless casing, the resulting product was a marvel of modern engineering. It’s monocoque titanium case, L-shaped gasket, and unique shrouded design were all firsts in the industry.
The result was a watch that was impervious to helium gas penetration, and one that could withstand the pressure of massive depths up to 600m. It instantly became a modern classic for Seiko, and has been in continuous production for the last 42 years.
The Tuna has evolved over the years, although many of the modern incarnations share the iconic design of their predecessors. Available in a variety of sizes, materials, and colors, the Seiko Tuna is an extremely collectible model with a rich history and an affordable price-point.
Today, the Seiko Tuna is powered primarily by Seiko’s innovative 7C46A quartz movement. Although many purists will look down upon the fact that the majority of Seiko Tuna’s are battery powered, a deeper look suggests that this unique movement is one of the most robust and highest quality quartz movements money can buy.
Let’s take a deeper look.
Seiko Tuna Movements
| Reference | Type | Jewels | Rate | Power | Hacking | Day | Date |
|---|---|---|---|---|---|---|---|
| 6159A | Automatic | 25 | 36,000 bph | 46 hours | |||
| 6159B | Automatic | 25 | 36,000 bph | 60 hours | |||
| H558 | Quartz/Digital | 3 | 3600 bph | 3 years | |||
| 8L35 | Automatic | 26 | 28,800 bph | 50 hours | |||
| 8L55 | Automatic | 37 | 36,000 bph | 55 hours | |||
| 7549A | Quartz | 5 | 3600 bph | 3 years | |||
| 7C46A | Quartz | 7 | 3600 bph | 5 years | |||
| 5R65 | Spring Drive | 30 | 32,768 Hz | 72 hours |
The Seiko Tuna series primarily utilizes Quartz movements, with the exception of the early models (“The Grandfather Tuna”) and some of the higher-end modern incarnations (namely the “Emporer” and “Hockey Puck”, which utilize the 8L35 and 6159 respectively). These high-end quartz movements are not your average $25 Chinese quartz module, they are designed specifically for the Tuna by Seiko and are incredibly accurate and reliable.
The most common movement found in these watches is the Seiko 7C46, a 7-jewel high-torque quartz movement with a 5-year battery life. These movements are designed by Seiko in-house and not utilized in watchs from any other brand. They are fully serviceable, anti-magnetic, and incredibly energy efficient. It is easily one of the highest quality quartz movements that money can buy.
The 8L35 movement found in the “Emporer Tuna” is an undecorated derivation of the Grand Seiko 9S55, a highly-accurate mechanical movement with a 28,800 beat rate and a 50 hour power reserve. It’s a high-end movement utilized in some of the best Grand Seiko dress watches, although lacking some of the polish and finishing. Since these watches do not have display casebacks, it’s a perfectly acceptable trade-off for the increase in performance.
The new Seiko Tuna SBDB009 and SBDB013 contains Seiko’s incredible spring drive movement. It’s a quartz/automatic hybrid that has such a high beat rate that it appears to glide continuously around the dial. Additionally, this movement has a power reserve indicator, lacks the ‘day’ window, and places the date between the 20 and 25 minute demarcations. It is considered by many to be one of the most technically impressive Seiko movements.
The automatic Tunas are an excellent choice for mechanical movement afficianados. I would argue, however, that the Quartz movement found in the majority of these models is the superior choice. Their accuracy and reliability make it a perfect fit for a tool watch of this caliber.
Seiko Tuna Quick Comparison
| Reference | Code | Nickname | Material | Depth | Size | L2L | Thickness |
|---|---|---|---|---|---|---|---|
| SAD018 | H558-500X | “Arnie / Arnold” | Steel / Plastic | 150m | 45mm | 46.5mm | 11.3mm |
| SAD017 | H559-500X | “Orange Arnie” | Steel / Plastic | 150m | 45mm | 46.5mm | 11.3mm |
| PYF028 | 7549-7010 | “Tuna Can” | Steel / Steel | 300m | 47.1mm | 44.3mm | 15mm |
| SBBN007 | 7C46-7011 | “Tuna Can” | Steel / Steel | 300m | 47.2mm | 44.5mm | 15.1mm |
| SBBN015 | 7C46-0AC0 | “Tuna Can” | Steel / Steel | 300m | 47.6mm | 44.4m | 15.1mm |
| SBBN017 | 7C46-0AC0 | “Tuna Can” | Steel / Steel | 300m | 47.6mm | 44.4m | 15mm |
| SBBN031 | 7C46-0AG0 | “Tuna” | Titanium / Ceramic | 300m | 48mm | 48.5mm | 14.7mm |
| S23155J | 7C46-6009 | “Ashtray” | Steel | 600m | 49mm | 44mm | 15mm |
| YAQ028 | 6159-7010/19 | “Grandfather Tuna” | Titanium / Ceramic | 600m | 50.5mm | 52.2mm | 15.9mm |
| PYF018 | 7549-7000 | “Golden Tuna” | Titanium / Ceramic | 600m | 49.2mm | 48.4mm | 16mm |
| SBDB013 | 5R65-OAK1 | “Spring Drive Tuna” | Titanium / Titanium | 600m | 49.60mm | 50.70mm | 16.2mm |
| SBDX005 | 8L35-0030 | “Hockey Puck” | Titanium / PVD | 600m | 52mm | 51.5mm | 16.23mm |
| SBBS018 | 7C46-7009 | “Golden Tuna” | Titanium / Ceramic | 1000m | 49.1mm | 48.6mm | 16.1mm |
| SBBN011 | 7C46-0AA0 | “Darth Tuna” | Titanium / Ceramic | 1000m | 49.2mm | 48.5mm | 15.9mm |
| SBBN00E | 7C46-0AA0 | “Robert F. Marx LE | Titanium / Ceramic | 1000m | 49.2mm | 48.5mm | 15.9mm |
| SBBN013 | 7C46-0AA0 | “Darth Tuna” | Titanium / Ceramic | 1000m | 49.2mm | 48.5mm | 15.9mm |
| SBBN019 | 7C46-0AA0 | “Dolphin” | White Ceramic | 1000m | 49.2mm | 48.5mm | 15.9mm |
| SBDX011 | 8L35-0030 | “Emporer Tuna” | PVD Titanium | 1000m | 51.9mm | 52.8mm | 17.2mm |
| SBBN021 | 7C46-0AA0 | “Blue Ocean Tuna” | Blue Ceramic | 1000m | 49.2mm | 48.5mm | 15.9mm |
Analog/Digital Seiko Tunas
The Ana-digi Tunas from the early 80’s have been lovingly nicknamed “Arnies” by hardcore Seiko fans. This funky vintage shrouded diver was worn by Arnold Schwartzenegger in a bunch of his action movies (Predator, Raw Deal, Commando, Running Man, and Twins). Whether you’re a Seiko fan or a classic action movie fan, this is a great model to grab.
It utilizes the H558 movement, which is a basic 3-jewel quartz movement with a module for an LD display at the top of the dial. It has a digital alarm and chronograph functionality, a plastic shroud, and a bi-directional bezel, making it a very unique entry in the series. It is available in both black and orange.
SAD018 (Arnie) |
|
|---|---|
 |
|
| Model: SAD018 |
Code: H558-500X |
| Size: 45mm |
Lug to Lug: 46.5mm |
| Material: Stainless Steel |
Shroud: Plastic |
| Depth: 150M |
Thickness: 11.3mm |
| Ebay (US) | Find SAD018 on WatchPatrol |
| Basic ana-digi watch with alarm, chronograph, and three-handed quartz movement. Does not have a day/date display, that functionality is placed in the LCD. | |
SAD017 (Orange Arnie) |
|
|---|---|
 |
|
| Model: SAD017 |
Code: H559-500X |
| Size: 45mm |
Lug to Lug: 46.5mm |
| Material: Stainless Steel |
Shroud: Plastic |
| Depth: 150M |
Thickness: 11.3mm |
| Ebay (US) | Find SAD017 on WatchPatrol |
| Similar to the H558 but with an orange face, much rarer than the H558. | |
300M Seiko Tunas
The 300M Tunas are the heart of the Seiko Tuna line, and by far the most common and collectible models. The majority of these models have a stainless steel case and a stainless steel shroud, with the exception of the SBBN031 which is titanium and ceramic.
Seiko was actually the first company to utilize Titanium in their watch construction, a material that is highly corrosion resistant and light-weight, making it a highly functional choice for a dive watch meant to be exposed to the elements.
The SBBN015 and SBB017 are the most popular of the “last generation” Tunas, and are differentiated simply by the color of the date wheels and the bezel.
PYF028 (Tuna Can) |
|
|---|---|
 |
|
| Model: PYF028 |
Code: 7549-7010 |
| Size: 47.1mm |
Lug to Lug: 44.3mm |
| Material: Stainless Steel |
Shroud: Stainless Steel |
| Depth: 300M |
Thickness: 15mm |
| Ebay (US) | Find PYF028 on WatchPatrol |
| First released in 1978, these were the first quartz watches Seiko produced. This iconic style has been maintained in many of the modern Tuna watches | |
SBBN007 (Tuna Can) |
|
|---|---|
 |
|
| Model: SBBN007 |
Code: 7C46-7011 |
| Size: 47.2mm |
Lug to Lug: 44.4mm |
| Material: Stainless Steel |
Shroud: Stainless Steel |
| Depth: 300M |
Thickness: 15.1mm |
| Ebay (US) | Find SBBN007 on WatchPatrol |
| This model has a unique dial with its 'crop-circle' markers. It has a stainless steel bezel and bead-blasted stainless steel shroud. | |
SBBN015 (Tuna Can) |
|
|---|---|
 |
|
| Model: SBBN015 |
Code: 7C46-0AC0 |
| Size: 47.6mm |
Lug to Lug: 44.4mm |
| Material: Stainless Steel |
Shroud: Stainless Steel |
| Depth: 300M |
Thickness: 15.1mm |
| Ebay (US) | Find SBBN015 on WatchPatrol |
| This modern tuna is based off the design of the 7549-7010, but has a black bezel. | |
SBBN017 (Tuna Can) |
|
|---|---|
 |
|
| Model: SBBN017 |
Code: 7C46-0AC0 |
| Size: 47.6mm |
Lug to Lug: 44.4mm |
| Material: Stainless Steel |
Shroud: Stainless Steel |
| Depth: 300M |
Thickness: 15mm |
| Ebay (US) | Find SBBN017 on WatchPatrol |
| Modern incarnation of the 7549-7010. Has recently been replaced by the sbbn031 and will likely go out of production | |
SBBN031 (Tuna Can) |
|
|---|---|
 |
|
| Model: SBBN031 |
Code: 7C46-0AG0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: Ceramic |
| Depth: 300M |
Thickness: 14.7mm |
| Ebay (US) | Find SBBN031 on WatchPatrol |
| The current Tuna model in production, it's currently divided fans with its dial and bezel updates. Some do not like the changes made on the iconic handset, but it is supremely legible nonetheless. It also has a couple of variations: the SBBN033 (silver bezel) and SBBN035 (DLC) | |
600M Seiko Tunas
The 600M range of Tunas contains a few oddities. The “Ash Tray” eschews the classic shroud for a scalloped titanium bumper. The “Golden Tunas” introduce rose gold accents on the bezel and crown. And the “Hockey Puck” is an absolute monstrosity, coming in at 52mm in size and 16.23mm in thickness, better left to the large-wristed among us.
Of note in this range is the “Grandfather Tuna”. This particular model was the first Tuna released in 1975, and broke all kinds of technological barriers with its titanium case, L-shaped gasket, ceramic-coated shroud, and vented rubber strap. Additionally, it’s one of the only Tuna models with a mechanical movement. These are exceedingly rare these days, and you’re going to have to pay a premium if you want to get your hands on one.
S23155J (Ash Tray / UFO) |
|
|---|---|
 |
|
| Model: S23155J |
Code: 7C46-6009/10 |
| Size: 49mm |
Lug to Lug: 44.4mm |
| Material: Steel / Titanium |
Shroud: None |
| Depth: 600M |
Thickness: 15mm |
| Ebay (US) | Find S23155J on WatchPatrol |
| Unique shroudless Tuna with a large titanium bumper around the case. Hard to find in good condition. | |
YAQ028 (Grandfather Tuna) |
|
|---|---|
 |
|
| Model: YAQ028 |
Code: 6159-7010/19 |
| Size: 50.5mm |
Lug to Lug: 55.2mm |
| Material: Titanium |
Shroud: Ceramic Titanium |
| Depth: 600M |
Thickness: 15.9mm |
| Ebay (US) | Find YAQ028 on WatchPatrol |
| First Tuna ever produced in 1975. Unique automatic movement. Very expensive. | |
PYF018 (Golden Tuna) |
|
|---|---|
 |
|
| Model: PYF018 |
Code: 7549-7000 |
| Size: 49.2mm |
Lug to Lug: 48.4mm |
| Material: Titanium |
Shroud: Ceramic Titanium |
| Depth: 600M |
Thickness: 16mm |
| Ebay (US) | Find PYF018 on WatchPatrol |
| The first of the Tunas to feature this classic design. Featured im the James Bond 007 movie 'For Your Eyes Only' in 1981. (image courtesy of Tantankian Watches) | |
PYF018 (Golden Tuna) |
|
|---|---|
 |
|
| Model: PYF018 |
Code: 7549-7009 |
| Size: 49.2mm |
Lug to Lug: 48.4mm |
| Material: Titanium |
Shroud: Ceramic Titanium |
| Depth: 600M |
Thickness: 16mm |
| Ebay (US) | Find PYF018 on WatchPatrol |
| Similar to the 7000, but built for the international market. Differences include the 'Battery Change Ring' on the caseback and the 'Divers' print at 6 o'clock. | |
SBDX005 (Hockey Puck) |
|
|---|---|
 |
|
| Model: SBDX005 |
Code: 8L35-0030 |
| Size: 52mm |
Lug to Lug: 51.5mm |
| Material: Titanium |
Shroud: PVD Titanium |
| Depth: 600M |
Thickness: 16.23mm |
| Ebay (US) | Find SBDX005 on WatchPatrol |
| Limited to 1000 units. One of the most saught after Tunas due to it's rarity. Reissue of the 6159 hi-beat Tuna. | |
SBDB013 (Spring Drive Tuna) |
|
|---|---|
 |
|
| Model: SBDB013 |
Code: 5R65-OAK1 |
| Size: 49.6mm |
Lug to Lug: 50.7mm |
| Material: Titanium |
Shroud: PVD Titanium |
| Depth: 600M |
Thickness: 16.2mm |
| Ebay (US) | Find SBDB013 on WatchPatrol |
| The incredible spring drive tuna is available in three variations. The SBDB009 is a gold accent version of this watch, and the SBDB013 and SBDB009 are nearly identical, swapping the Seiko 'S' crown for a Prospex 'X' crown. | |
1000M Seiko Tunas
The 1000M Tunas are the most functionally robust models in the line and contain a few unique variations and special editions. The “Darth Tuna” is named for it’s insidious black case and shroud, and the “Dolphin” and “Blue Ocean” introduce a few brightly colored ceramic shrouds to the lineup.
Most notable in this range is the “Emporer Tuna”, an absolutely massive titanium dive watch powered by an incredible GS derived mechanical movement (the 8L35). This is the boss-man of the Tuna line-up and not to be trifled with by those with small wrists or small egos.
SBBS018 (Golden Tuna) |
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|---|---|
 |
|
| Model: SBBS018 |
Code: 7C46-7008 |
| Size: 49.1mm |
Lug to Lug: 48.6mm |
| Material: Titanium |
Shroud: Ceramic |
| Depth: 1000M |
Thickness: 16.1mm |
| Ebay (US) | Find SBBS018 on WatchPatrol |
| Gold bezel and crown. Produced in 1991. | |
SBBN011 (Darth Tuna) |
|
|---|---|
 |
|
| Model: SBBN011 |
Code: 7C46-0AA0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: Ceramic |
| Depth: 1000M |
Thickness: 15.9mm |
| Ebay (US) | Find SBBN011 on WatchPatrol |
| One piece monocoque case, PVD coated titanium. Flat AR-coated sapphire instead of the domed hardlex. (image courtesy of Tantankian Watches) | |
SBBN00E (Robert F. Marx LE) |
|
|---|---|
 |
|
| Model: SBBN00E |
Code: 7C46-0AA0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: Ceramic |
| Depth: 1000M |
Thickness: 15.9mm |
| Ebay (US) | Find SBBN00E on WatchPatrol |
| Limited to 300 pieces. Collaboration with Robert Marx, a marine archaelogist. Same as the Darth Tuna but with a unique dial. | |
SBBN013 (Darth Tuna) |
|
|---|---|
 |
|
| Model: SBBN013 |
Code: 7C46-0AA0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: Ceramic |
| Depth: 1000M |
Thickness: 15.9mm |
| Ebay (US) | Find SBBN013 on WatchPatrol |
| Identical to the SBBN011 except for the 'Marine Master' branding on the dial and signed crown. | |
SBBN019 (Dolphin) |
|
|---|---|
 |
|
| Model: SBBN019 |
Code: 7C46-0AA0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: White Ceramic |
| Depth: 1000M |
Thickness: 15.9mm |
| Ebay (US) | Find SBBN019 on WatchPatrol |
| Unique Limited Edition Tuna with a white ceramic shroud. 300 pieces worldwide. | |
SBBN021 (Blue Ocean Tuna) |
|
|---|---|
 |
|
| Model: SBBN021 |
Code: 7C46-0AA0 |
| Size: 49.2mm |
Lug to Lug: 48.5mm |
| Material: Titanium |
Shroud: Blue Ceramic |
| Depth: 1000M |
Thickness: 15.9mm |
| Ebay (US) | Find SBBN021 on WatchPatrol |
| Unique Tuna with a blue ceramic shroud. 130th anniversary edition. Blue accents on the dial. | |
SBDX011 (Emporer Tuna) |
|
|---|---|
 |
|
| Model: SBDX011 |
Code: 8L35-0030 |
| Size: 51.9mm |
Lug to Lug: 52.8mm |
| Material: Titanium |
Shroud: PVD Titanium |
| Depth: 1000M |
Thickness: 17.2mm |
| Ebay (US) | Find SBDX011 on WatchPatrol |
| Largest of the Tunas but features a high-end Grand Seiko automatic movement | |
Overall, the Seiko Tuna is a must-own for any serious tool watch afficianado. It’s lugless design makes it comfortable for any wrist size, and it’s no-nonsense toolish design is backed up by serious dive watch capabilities. Whether you’re a saturation diver or a desk diver, this watch has serious collector appeal and belongs in the conversation with much more expensive competitors.
Please let us know if we’ve missed any of your favorite Tuna models in the comments below!
About the Author
Comments 19
There are at least 2 that are missing you might want to list Mike. SBDX014 and SBDX016
Hey Mike, can you please credit my pictures… The golden tuna 600m and the sbdx011 from http://tantakian.com
Author
Done! Thanks for the heads up.
Hi Mike, nice Tuna guide!!!
One question, how was your measurement data gathered (Size-L2L-Thickness)?
Did you put calipers on the actual watches or just find the data online?
I don\’t know if you wished to include LE models, but you do call this \”The Ultimate Seiko Tuna Collector’s Guide\”, and for collectors wanting to use this as the \”ultimate\” reference it should be definitive.
Missing – 300m
SBBN023 – GOLGO 13 – LE of 500
SBBN00C 1999 SCUBAPRO – LE of 300
DIME MD – LE of 50
SBBN037 – Blue Tuna
SBBN039 – PADI Tuna – LE of 700
600m edit
SBDB008 – no mention of the SBDB008, the SBDB009 isn\’t the gold accent version the SBDB008 is. (probably just a typo)
Missing 1000m + Edits
SBBN011 – your image is actually an SBDX011 (Emperor Tuna) not an SBBN011 Darth Tuna.
S23619J1 – Export Darth Tuna (worth mentioning as it does exist)
SBBN025 – replaces SBBN013
SBBN027
SBBN029 – Platinum Ocean – 50th Anniversary – LE of 700
Author
Thanks for the feedback Mike! I’m updating the guide now to include these rare models.
Missing the 5m23-6a19 and 5m23-6a10 baby tunas.
Hi Mike
I believe the diver complained to Seiko about the current dive watches being unsuitable for saturation diving in 1968.
Seiko watchmakers then worked on new designs and solutions and released the watch in 1975.
I just purchased a marine master 1000 quarts while in Japan, it is a limited run of the original 1978 design but I’m unsure of how many they have produced any info out there. I understand they only made 500 available to the US, in purchased mine in Okinawa and was treated like a millionaire after my purchase. Mine is #0199. Pricy but worth every penny. Any info out there?
Do you know the model #? Because Seiko re-released the iconic Gold tuna last year, and although there were like ~2k, I don’t think they are that rare. I don’t even think all of them were sold. THis is the same for the SBBN039 (PADI) as well as the newest pink tuna (SBBN042)
Its not impossible that you have long abandoned this article but I really love your efforts
That said, you are missing ALOT of Tunas.
For instance, 2 brand new Gundam related ones were released a month or so again, as well as the Gold reissue + new pink tuna from last summer.
Solar tunas (redesigned) is very popular now too. Seiko has basically been releasing them as fast as Omega releasing SE Speedys.
You also missed alot of 300M and 1000M Tunas. For instance, SBBN039 (PADI), SBDX Tunas, and more.
Is the Seiko Tuna Can SBBN031 still in production as of July, 2019?
SBBN031 is stainless steel, not ceramic shroud and titanium case.
Why don’t just one of you guys complete a comprehensive list of all the Marinemaster Tunas that have been released? Like Mike’s list of missing watches in the guide but containing all of them. I’m very far from an expert but can still find releases that neither of you have mentioned..
I have a brand new sample Tuna case but no movement. Seiko USA has a policy that they will fix your movement, but won`t sell you one. Anybody have a movement for my 1000m Tuna? It`s the quartz version.
Good job on this great article !
Just a little detail, the letter from the pro diver from Kure port was from 1968 😉
The Tuna being released in 1975, the letter had to arrive earlier !
Thanks for sharing the Tuna love !
Seiko reference for Golden Tuna is actually SSBS018 (not SBBS018) .
Great resource page, thanks for sharing.
Nick Hacko
Hello!
I figured as long as this guide was up I would comment. Regarding this Ref: SBBN031 above. Every spec you mentioned is wrong. Lug to lug, case dimensions and metal materials are all wrong.
Cheers.
Great guide
There are some 300m Tunas missing
They are
SBBN037 – Blue dial and blue bezel insert
SBBN039 – PADI edition
The SBBN001/033/035/037/039 series were discontinued in early 2020 and new 300m models with hands and dial like the 7549/SBBN007/015/017 and a sapphire crystal were released
They are:
SBBN043- Blue dial/blue bezel insert
SBBN045- Black dial with black bezel insert with strap (the replacement for the SBBN031)
SBBN047- Black dial with silver bezel and a bracelet (replaces the SBBN033)
(Interestingly enough, while the SBBN045 and SBBN047 replace the SBBN031 and SBBN0033, the bracelet and strap are reversed with the silver bezel SBBN047 getting the bracelet (while its predecessor 033 had a strap) and the black bezel insert SBBN045 getting a strap (the previous SBBN031 got the bracelet)
Calling all Tuna experts – is there a no-date Tuna? I have completely gone off watches with a date.