Monday, 5 January 2015

Review: Seiko Prospex "Baby Tuna" SRP637K1 200m Diver

"Bekkk... aku ada satu. Model baru. Macam Tuna! That was what my fellow H4U blogger Hassan Detikduabelas told me. Actually, I haven't bought any brand new watches for almost two years! Curious... I asked him to send me the photos. Wow! From the photos, I know this must be big - a masculine diver. It looks like the famous Tuna diver. It looks like the Seiko Monster too. Browsing Yeoman's Seiko website I found that this newly launched diver interesting. Hah haa... curious, I can't wait to see the real thing. I called Hassan, agreed, we met after midnight on January the 3rd. Midnight!? We actually met early morning on January the 4th! The real deal is to get my new year's watch. Not so expensive but the quality worth to pay with thick fifty ringgit bill! Thanks bekk... jam ni memang cunnnn.... hah ha. He suggested to me, bek... buat review simple simple jehh!!! Hee hee... I guest I don't have much time blogging lately, read my simple pictorial review of this what they call the 'Baby Tuna" diver. Hmmmhhh... Baby Tuna? I guess this hybrid of Tuna and Monster diver would be more appropriate to associate with an incident where a monster stuck in a tuna can! Joking... read my pictorial review on this shrouded diver SRP637K1. Enjoy..." - thetick-thetick

Model No: Seiko Prospex SRP637K1 200m Diver
Movement: Calibre 4R36, 24 jewels, hacking for time-setting, 3 hands - hour, minute & second, and day-date display
Driving System: Automatic and hand-winding
Vibration: 21,600 vph/bph
Power Reserve: approx. 41 hours, continuous operating time
Magnetic Resistant: 4,800 A/m (60 gauss)
Watch Case: Stainless Steel, 47.5 mm diameter excl crown, 14 mm thickness, 50 mm lug-to-lug
Watch Lug: 22 mm
Watch Crystal: thick flat Seiko Hardlex mineral glass
Scuba Bezel: Stainless Steel engraved, 120 clicks uni-directional
Case Back: screw down diver case lid
Bracelet: Stainless Steel 22-20 fitted with Seiko diver's clasp with wet suit extension
Water Resistant: 200m

Using the Seiko Monster's typical dial and engraved bezel, the 'Baby Tuna' diameter extended by the stainless steel shrouded case. 47.5 mm! Not too big and not too ordinary. Well, nowadays... big is beautiful!

Side profile. See from the crown side, typical Tuna with 14 mm thickness. Rugged but the outer shrouded case is beautifully constructed with satin-brush finishing. The unsigned screw-down crown is well protected under the outer case - perfectly fitted. The outer case can be detached. Look at the watch shoulder... so recessed to allow the case to wrap nicely on the wrist. I like bro... you know why? My wrist is not that big laa...

Look at this masculine baby! Baby? Yaa... smaller than the standard Tuna maybe... he he. I like to see the watch from this angle. It shows the entirety of a solid modern diver's watch construction. 

The other side... see the two big screws and the space to expose the bezel tooth for time-elapse setting. Hmmhhhh... looks like a crab!

Another side profile. Look at the shoulder from this angle. The symmetrical design for both lugs is superb. A very solid construction... but bro, isn't it looks heavy?

The case shoulder and the lug... the shorter lug is proportionate with the watch case and height.

The case back. Standard. But look at the diameter extension. The outer shrouded case enlarges the watch base. Sorry brader... jam baru. Wa tak bukak lagi plastic kat penutup tuu... Jangan marrah heh!

The screw-down crown is protected by the outer case.

Like Sumo... like Monster, using the SS bracelet clasp with wet suit extension

The watch crystal is flat - thick mineral glass. Look at the minute index. Very clean and visible.

Fitting the SS bracelet. This Baby Tuna is resting like a giant. Grab one! See this recently released shrouded diver in action. Don't ask me about the performance of 4R36 Seiko work horse. It is proven and reliable movement enhanced from the 7S26 caliber.

My wrist is not that big. But this Baby Tuna wrapped nicely around my wrist. Thanks to the recessed and short case shoulder. A truly beautiful construction that can fit smaller or bigger wrist.

Side by side with other sibling... the Baby Tuna and the Sumo. Looks almost similar size. The time-keeping work horse! 4R36 is powering the Baby Tuna... 6R15 for the Sumo.

"Cunn braderr.... cunnn. Bek, kalau ada orang nak order camna? Hehe, soalan aku pada Hassan Detikduabelas. Rasanya boleh dapat... replied Hassan. Actually this newly released mid-entry level diver is new to the Malaysian market. Honestly, I like it a lot. It is an affordable big shrouded diver. Compared to the current Monster line, this one is really masculine with good aesthetic design for a modern diver. I guess this should be the real Monster for the 200m diver's line - not the normal Monster we have seen previously. Check-out for other variants that come with various cosmetics and Z22 strap. Okies, hoped you guys enjoy this pictorial review. Bek! Amacam? Okey tak review aku nih? My first article for 2015. Happy new year to fellow H4U bloggers and my blog followers. Wait for my next article." - thetick-thetick  


  1. finally... been waiting so long. Love to read your watch review. Welcome back Radzi

  2. TQ. Sorry, I was busy surviving my business. Hopefully 2015 have more free time to blog :-)

  3. Thanks for your wonderful review. I will consider buying this watch next month when I have saved enough money. This watch was recommended by the salesgirl at MPT City Square, Johor Bahru, it costs RM1680 but after less 30% discount costs RM1176.

    May I ask since this is an automatic watch, how long is the power reserve if I don't wear the watch? And is there a kinetic version of this watch?

    Thanks bro.


  4. Hi Rainer,

    Sorry late reply. The power reserve in 42 hours continuous operation. Meaning, if you use or normal wear for one day, once you don't use it it will last for 42 hours. RM1,200 or below is a good price.

    1. Is model no. Seiko Prospex SRP637K1 200m Diver 100% made in Japan?

  5. Is model no. Seiko Prospex SRP637K1 200m Diver 100% made in Japan?


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