Monochrome Watches
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Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ 4R36 (Black ref. SRP655K1 & Blue ref. SRP653K1) – Review with Live photos & Price

| By Brice Goulard | 5 min read |

The Seiko ‘Baby Tuna’ is back and more strong than ever. The watch that is known with this nickname is a true icon from the Japanese brand Seiko, the affordable edition of the impressive and professionally oriented MarineMaster Tuna, with its very qualitative construction. However, the Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ might be a lot cheaper, it also has the ‘Prospex‘ (meaning the Seiko Professional Specification) name written on its dial and all the attributes of a proper Seiko: solid, fully developed and manufactured in-house and a great value for money. Say hello to the new 2015 Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ 4R36 ref. SRP655K1 (black) and ref. SRP653K1 (blue). 

The range of dive watches by Seiko is wide but all the editions are full of interest. Starting from cheap (under 300 Euros) but solid beaters like the Seiko SKX007 to more well constructed watches like the Seiko Monster, proper tools like the Seiko SBDC007 or finally real professional watches like the Seiko MarineMaster 300 or MarineMaster Tuna 600 (yes, the range is wide), they all share the Seiko spirit, with their unbeatable quality / price ratio and their clear professional intentions. The new Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ introduced during Baselworld 2015 is clearly a watch that collectors with smaller budgets will for sure like – and buy.

Seiko Prospex Automatic Diver 200m blue SRP653K1 - 1

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This new Seiko ‘Baby Tuna’ (as collectors like to call it) is part of the Prospex collections, meaning that it fulfills the difficult Seiko Professional Specifications. Everything started back in the 1960s, when SCUBA diving was on the rise. In 1965, Seiko introduced their first professional dive watch, the renown 6217, with a rotating bezel and a 150m water-resistance (more to read about it here, here and here). From now on, a part of the collection was build with the only intention to seduce professional divers and to fulfill their needs with purposely build watches. PROSPEX watches are not to be confused with Seiko’s standard mechanical line-up of watches. The build quality of these watches are far from cheap and Seiko’s PROSPEX is also one of the leading innovators in terms of dive watch advancement. Knowing that the 2015 Seiko Prospex Automatic Diver 200m has this mention on its dial should be the insurance of quite an interesting watch.

Seiko Prospex Automatic Diver 200m black SRP655K1 - 2

What is it about? This 2015 Seiko ‘Baby Tuna’ is the new edition of an icon, a watch with a true aura and its very personal design, recognizable among dozens of divers. It’s also a beast with its 50mm case. But once again, it’s part of its DNA and its purpose. The 2015 ‘Baby Tuna’ comes with the specific case, composed of a round stainless steel central part, with a curved caseback – a case called ‘scallop’ – that shows no protruding lugs. The other specification of this watch is the shape of its upper case, with an incomplete shroud that both protects the case and rotative bezel and also allows to perfectly grip this bezel, even with diving gloves (don’t forget the professional orientation of this watch). This added protective shroud is made of Stainless steel with a black or blue ‘Hard-Coating’ that should be ceramic (as the caseback indicated the use of such material). Previously made of plastic, this new material increases the overall quality.

Seiko Prospex Automatic Diver 200m black SRP655K1 - 1

The bezel is classical, as it rotates unidirectionally and its engraved with a 60-minute scale. Its is made of metal coated with a glossy black or blue laquer (depending on the edition) and large white markers and numerals. It also has some large and easy to grip deep groves to facilitate the prehension. The bezel is thus easy to operate and to read. This also goes for the dial. With its large luminous indexes and hands, it is a legible and practical tool even under the deep blue seas. Compared to the previous edition, the indexes are now round and triangular (for the quarters) instead of straight batons. The hands are also large and highly legible. As usual, the caseback and the crown are screwed to ensure the 200m water resistance.

Seiko Prospex Automatic Diver 200m black SRP655K1 - 4

Inside the ‘scallop’ case ticks a well known self-winding movement, the Seiko 4R36, a 24 jewels calibre, with hand-winding capability and 41 hours of power reserve. It ticks at a reasonable 21.600bph. This movement introduced in 2011 replaces the iconic 6R15 (that finds its roots in the 7S26 that equipped a large part of the Seiko divers from 1996 to now, including the very cool Seiko SKX007) and as it shares lots of its specifications, we can expect this 4R36 to be also reliable and efficient. As every of the movements cased into a Seiko, we’re talking about real in-house / manufacture movements, meaning that it was fully designed, developed and build by Seiko, with the rigorous Seiko standards. The Seiko 4R36 displays the hours, the minutes, the seconds on the central axis and two calendar indications; the date and the day, in a window at 3.

Seiko Prospex Automatic Diver 200m blue SRP653K1 - 2

With a 50.2mm diameter, we won’t hide the fact that the Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ is a huge watch – not to say a monster. It will certainly be more practical over a diving suit than on the wrist of an elegant gentleman wearing a tuxedo. However, this size is part of the DNA of the ‘Baby Tuna’ and, thanks to the curved caseback, to the soft silicone band and to the lack of external lugs, the comfort is here – and considering the success of the previous editions, this diameter will never be a barrier for collectors. This Seiko Prospex Automatic Diver 200m is available in two editions, a black one with black strap and indexes circled in red – ref. SRP655K1 – and a blue one with blue strap and indexes circled in white – ref. SRP653K1.

Seiko Prospex Automatic Diver 200m blue SRP653K1 - 3

Now comes the question of the price… Take a look back at the article and the photos, consider the in-house self-winding movement, the functions, the 200m water resistance, the quality of the case and the PROSPEX indication on the dial. If we were talking about a Swiss watch, we could have expect a minimum of 2K Euros – or a least a price with 4 figures. Well, don’t forget that Seiko watches are great value for money because this 2015 edition of the Seiko Prospex Automatic Diver 200m ‘Baby Tuna’ ref. SRP655K1 or ref. SRP653K1 is priced at 629 Euros in Europe (including taxes). Quite a good deal isn’t it?

More on Seiko and Seiko Prospex.

20 responses

  1. I think the blue Seiko is one of the nicest watches I have ever seen. And I have Breitling superoceans, Titanium seawolfs, vintage all original turtles and modern done up ones with all the top add-ons. Plus doxas and rolex seadwellers etc. My only issue is where do u send a valuable seiko for a service? All the other companies have their own (overpriced) service locations so all I do is walk into my jeweller and say send that off for me. With seiko anything over a few hundred pounds (and I love the cushion body turtles) its just too much of a risk posting to a stranger and ‘real’ dive watches need real services. I just spent 3 weeks down at 100m wearing my seawolf and before I went I had Breitling run all their tests. What people dont accept it the watch can cost £3500 but if a gasket worth 10p goes its no better than a cheap watch. All the other guys just wear casio G-shocks for recreational diving and proper dive computers for helox dives. Anyway, I love the Seiko and must have it,lol Paul 🙂

  2. This piece is so boisterious looking to be a nice dress watch, but it’s very cool as a diving watch. I really love the Tsunami logo on the case back, it’s a masterpiece of Katsushika Hokusai – The Great Wave off Kanagawa (Kanagawa Oki Nami Ura)

  3. I have the seilko tuna sbbn015 and brought the seiko black srp 655k1
    This watch seems better built in my opinion.

  4. i have just bought my baby tuna blue today and it is a fantastic watch according to me and i will always wear it during a long time in the future night and day i am really happy buying this monster which is a limited edition for the 50 years of seiko diver watches in the world since 1965. this watch is compatible with my sports that i practice on the earth and into deep water. sincerrely it is really a very very good product of this seiko nippon manufacture. long life to me whith my seiko monster !! have a ggod year with your seiko monster baby tun black or blue and spend always everyday proudly with this robust piece of super technology. damien Seymour

  5. It is very timely acquisition of owning this very valuable time piece Seiko Prospex Automatic Divers 200 m, 4R36 bought at Angus & Coote, Westfield, Penrith, NSW, AUS. Actually, I bought another Seiko Divers Kinetic 200 m too, but I like most the Baby Tuna model. Now I can start spear diving at Wollongong sea coast.

  6. bought the SRP655 have many Seiko diers, this is my everyday watch. It is indeed large but wears like a smaller watch and keeps surprisingly accurate time for an auto. put on SS band and it really makes the watch pop

  7. I want to buy this watch,but I don’t like the strap.I want a titanium or steel bracelet wich size bracelet do I need 20mm 22 mm ? I looked at and but cannot find it.Thank you if anyone can help me,watch is for my boyfriend.The Seiko site has no info also.

  8. Hello, I bought one last month and it was so great. But now I think there are some probplems because it does not show the right day and calendar, when I put it back to the right day anđ calendar, after a little time it will turn wrong again, can you please expain me why and help me to fix it? Thank you very much!

  9. You just bring it to a official Seiko local watch store for repair .All Seiko watches have international warranty at least a year warranty,or just bring it for repair to the store where you bought the watch.The should help you and repair you’re watch for free,it falls under Seiko garanty.

  10. Hello..I just bought seiko 655k1 a few weeks ago….nice watches.Talking about someone say..a little problem…date and day not correct changing…..Actually…no problem…you neef to setting properly as a manual show.Then…day and date change accordingly…confirmed bro..

  11. Guys I have same problem like yours when I adjust the correct day and number because the prospex model has dual settings the English and arabic, spanish, japanese etc..but since seiko divers were popular in our place i know it’s difficult. Mind was English and Spanish. I did make it the correct setting for around 7 times of trial. the trick to correcting the day and date is careful pulling of the adjustment tuning. You should pull and feel the small click every time you adjust but if you don’t have the delicate sense then it’s better to bring it to store where you bought it or to the jewel repairman. Our watch is a good looking and a fine crafted time piece so congrats to all of us who have one on our wrist.The reason why I buy diver watch?… BECAUSE DIVER WATCH IS SOLID, STRONG, TELLS THE CORRECT TIME, HANDSOME AND SPECIALLY DURABLE TO DAILY COMPANION WITH LESS MAINTENANCE BELIEVE ME ALMOST MOST OF MY RELATIVE WORE SEIKO DIVERS SINCE 1980’S UNTIL KNOW IT’S FUNCTIONAL. IT IS ALSO CHEAP BUT THE PERFORMACE, THE FEEL AND THE LOOK TELLS SOMETHING..GOOD WORK SEIKO.

  12. It’s huge! I just can’t pull it off which is a shame as they are an absolute bargain automatic diver in the tuna can fold. Now have an Arnie and a SBNN035 which are a great size for most wrists and don’t be put off by quartz.

  13. I own one of the blue ones. Waited for years to get the right diver and am confident this is the real deal. Not pretty. Not a Sub clone. Just an instrument. It gains 3 to 4 seconds per day on-wrist.

  14. Brought it about two years ago. The watch started losing minutes, then hours. Sent it back to Seiko and they replaced the movement at my cost. A bit disappointed with the 4R36, maybe it is just bad luck on my part.
    BTW, the price of this watch seems to go up quite a bit according to ebay.

  15. I think it was just bad luck Tim, unless you were too harsh with it. Sounds like something was broken. Don’t forget, no matter how tough the case, a mechanical movement is still a delicate machine, full of tiny gears, and springs machined to micron tolerances. I broke several mechanical watches before I changed my habits, e.g. air-drumming to rock music with my headphones on! 🙂

  16. It’s not 41 hours for the power reserve, this value has been propagated throughout the social media, The actual value stated by Seiko in their guarantee is “36 hours fully wound”. If you buy a watch from a authorized dealer you’ll get the guarantee booklet stating this value for the 4R36 movement.

    Check my review at BushCampingTools and my very thorough blog.

  17. Just bought one to replace an earlier SKX 171. I use it to switch-off with my Omega Seamaster as a work watch. Really nice looking watch. I have owned a number of Seiko watches over the years and the finish on this one puts the others to shame.

  18. I just bought a seiko baby tuna special edition blue colour and i’m loving it very much😍😍😍.I’ve always like seiko watches,this is my third seiko watch😊😊😊

  19. ahhh… 2015, I remember walking to a watch shop and seeing this… headed straight to an ATM machine… should have bought both the black and the blue but the wife gave me the evil eye… 🙁 ended up buying just the blue one…

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