Seiko Sumo Vs Turtle – An Extensive Comparison

Seiko is fond of choosing the most fun names for its watches. Don’t you agree? For instance, in our last review, we looked at the Seiko Samurai vs Turtle. And today, we’re looking at the Seiko Sumo vs Turtle. Pretty interesting names, right? Samurai, Turtle, Sumo, and there’s even Tuna as well.

The name “Sumo” probably already reminds you of something. If it reminds you of a Sumo wrestler, then you’re not wrong. This is, in fact, why the Seiko Sumo is so named. On looking at it, you find that it is quite large and bulky, kinda built like a Sumo wrestler in short.

The Seiko Turtle isn’t a small watch either. In fact, it’s one millimeter wider than the Seiko Sumo in case diameter. So, we’re looking at two pretty large watches.

Now, while the Seiko Sumo and Turtle differ in a number of areas, they also look a lot alike. This is why today’s Seiko Sumo vs Turtle review will be looking into each of these watches to give you the accurate low down. We will help you decide on which of these watches should be yours with our in-depth review.

Since we have a lot to touch, we’d better get started. The Seiko Sumo vs Turtle begins now.

Table of Contents

Seiko Sumo Vs Turtle – Comparison Overview

Just in case you can’t spare the time to go through this review (it’s a really long one because it leaves no stone unturned), here’s a brief summary.

The Seiko Sumo and Turtle are both large watches that do not exactly look alike but do have a lot in common. You can easily spot the difference between both watches straight up in their shapes. The Sumo is just large. However, the Seiko Turtle takes the shape of a turtle’s shell, which is why it is so named.

Besides that, the movements of these watches are also pretty similar, although they are actually different movements.

The Seiko Sumo uses Seiko’s 6R15 while the Seiko Turtle uses Seiko’s 4R36. Basically, you’re getting the same things with these movements like hacking, manual winding, and 21,600 beats per hour. However, the 6R15 trumps the 4R36 in that it comes with a power reserve of 50 hours, while the 4R36 only comes with 41 hours.

But then again, the 4R36 also trumps the 6R15 from another angle. It comes with the day/date complication whereas the 65R15 only displays the date.

Both watches meet the ISO 6425 standards to the letter. So, as dive watches, they are good to go. They also feature bright lume hands, water resistance down to 200 meters, as well as unidirectional bezels.

So, overall, these two watches get a good grade on our scoring board. The Seiko Sumo might be a little better than the Turtle, but the difference is only slight. It has more power reserve time and a slightly narrower case diameter. But then again, it does not have as many models available as the Turtle.

Seiko Sumo Vs Turtle – Worth The Money?

They are definitely worth the money. And Seiko does not disappoint when it comes to that. Most of their timepieces are affordable. But Seiko also tries not to compromise on quality in spite of that. We can confidently tell you that, since we have reviewed a number of Seiko watches already. And who says you have to take our word for it? Check around for what people are saying and you’ll be able to confirm for yourself.

Of course, you can expect a few compromises here and there, these are sub-$1000 watches after all. The bracelet, for instance, isn’t the absolute best there is, neither is the crystal. Both are actually just mediocre at best. Plus, chapter ring misalignment is fairly common with these watches.

However, at the very core of these watches, is a hardworking engine that delivers. Plus, the watches last, that’s for sure. You’d hardly be needing a replacement soon. And trust us, we got the word on the street concerning this. People have used these watches for a decade. So, they are solid.

So, if you can look past those small cosmetic flaws, you’re definitely going to enjoy these babies. For sub-$1000 watches, these guys are well worth the money.

Seiko Sumo Vs Turtle – Comparison Of Major Specs And Features


Seiko Sumo

Seiko Turtle

Model Number SBDC SRP
Movement Seiko 6R15 Automatic Seiko Automatic 4R36
Display Analog Analog
Complications Date Day/Date
Case Stainless steel Stainless steel
Case Diameter 44 millimeters 45 millimeters
Case Thickness 13.3 millimeters 13.4 millimeters
Strap Stainless steel Stainless steel
Strap Thickness 20 millimeters 22 millimeters
Clasp Deployant with safety Deployant with safety
Bezel 120 click One Way Rotating Elapsed Timing Bezel 120 click One Way Rotating Elapsed Timing Bezel
Crystal Hardlex Hardlex
Water Resistance 200 meters / 656 feet / 20 Atmospheres 200 meters / 656 feet / 20 Atmospheres
Power Reserve 50 hours 41 hours
  Get the Seiko Sumo here! Get the Seiko Turtle here!

Video: Seiko Sumo vs Turtle

This video gives a detailed analysis of the Seiko Sumo vs Turtle comparison

Seiko Sumo Vs Turtle – Who should Get Which Watch?

Seiko Sumo

Seiko Turtle

The Seiko Sumo belongs to Seiko’s Prospex line. The Prospex is Seiko speak for professional specifications. So, they build these watches to meet professional standards for whatever their purpose.  

So, who should get the Seiko Sumo? First, someone with a pretty large wrist. Think about 7 inches at least because at 44 millimeters, this is a pretty large watch!  

Secondly, it’s also a great diver’s watch that meets ISO 6425 standards. We’ve heard a few people say they can’t use this watch to dive and we wonder why.

If you’re pressed for cash, and you need a diver’s watch that’s up to standard, you should be looking at Seiko. Plus being that this is the Prospex line, you’re actually getting pretty good quality for a fair price.  

Can this be your everyday watch? Yes, it can. Should you use it for formal occasions? Probably not. It could serve as a semi-formal watch though if you don’t mind the sporty look it has.
If the Seiko Sumo is large, then the Seiko Turtle is even larger. Plus, it has a more pronounced shape that stands it out. However, just like the Sumo, the Turtle can probably also function as your everyday watch.  

Since the Seiko Turtle has silicone rubber strap options, you could go for those if you are getting the watch strictly for diving. Thankfully, both the Sumo and Turtle give you the chance to change out your strap if you want. So, you can always get either the jubilee bracelet or the rubber strap and replace them with anything you want.

The Seiko Turtle will definitely work for the same users as the Sumo. It really boils down to personal preference in the end.  

However, because of its unique shape, we can see watch hobbyists getting this piece just for keepsake unlike the Seiko Sumo.
Get the Seiko Sumo here! Get the Seiko Turtle here!

Seiko Sumo Vs Turtle – Which Features Do They Have In Common?

Mind you, as we mentioned earlier, these guys have many areas where they are alike. So, it might run into a pretty long list.

See also  Seiko Samurai vs Turtle – Which Should You Get?


How does the case of the Seiko Sumo compare to that of Turtle

The cases of the Seiko Sumo and Turtle have a few differences. But in many aspects, they are similar. One of the differences is that the Seiko Sumo’s case measures 44 millimeters in diameter while the Seiko Turtle’s case measures 45 millimeters.

Another difference is that Seiko Turtle has a distinct shape for which it is named. It actually looks like a turtle. Some people love the looks of the Seiko Turtle, others couldn’t care less.

In comparison, the Seiko Sumo isn’t as wide or as flat as the Seiko Turtle. Instead, it’s got the tapering sides which helps the watch give a better hug around your wrists. And there is also the usual “Seiko tsunami” insignia on the back of the watch as well.

However, the case of the two watches have a lot of similarities. The back of their cases are made from stainless steel, with a brushed and polished effect on their side surfaces. And with the addition of screw-down lock, it completes the water-resistant benefit of these two watches.

Finally, the case makes these two watches quite large. They both measure above 13 millimeters in thickness.

Being this large, we doubt these watches would fit people with slender wrists. Plus, if you’re not exactly a fan of large watches, you might want to steer off either of these watches.


When looking at the dials of the Seiko Sumo vs Turtle, you’ll find a lot of similarities. Of course, there are differences in the styling of the hands and all that. However, at the very basics, the dials are pretty similar.

Dial Colors

Seiko Sumo

Seiko Turtle

The Seiko Sumo features a variety of models. Many have been discontinued. So, in this article, we will only be bringing up those that are still available for sale. Trust us, the comprehensive list of all Seiko Sumo watches is endless.  

Here are the various models and their dial colors.  

The Seiko Sumo SBDC031 comes with a black dial with white/gold markings.  

The Seiko Sumo SBDC033 comes with a blue dial and white markings.  

These are the two models of the Seiko Sumo currently available on most retail platforms.  

There are other super rare Seiko Sumo models like the Seiko Green Dial PVD Sumo, and the Seiko Yellow Sumo. You’d be lucky to get your hands on any of these.
Just like the Seiko Sumo, the Seiko Turtle also has many variations. Let’s check each of them out.  

The Seiko Turtle SRP777 and SRPC44 both have black dials with white markings.  

The Seiko Turtle SRP773 and SRP779 both share a navy blue dial with white markings.  

As for the Seiko SRP775, it comes with a black dial with gold/white markings.  

The Seiko SRP PADI edition features a blue sunburst dial with white/red markings.  

Lastly, there’s the Seiko Turtle SRPC65 which sports an orange dial with white markings.

Markings And Complications On The Dials

Seiko Sumo

Seiko Turtle

The markings on the Seiko Sumo representing the hours, minutes, and seconds are quite typical. That is, they are pretty much the same as markers you see on dive watches. There isn’t much difference.  

However, there are still a few things we found quite attractive. The minute and second markers are pretty similar. However, the attractive part of this watch’s dial is in the 12 O’ clock dial.  

In most Seiko Sumo watches, the 12 O’ clock marker comes in the shape of a rhombus partitioned down the middle with a downward stroke. This downward stroke could even extend into a cross shape in some models.  

That said, the minute and second markers lie in an outer ring that slides down and connects to the dial where the hour markers are found.  

Now, the complications. The complication on the Seiko Sumo is different from the one on the Seiko Turtle. This one only displays the day unlike the Seiko Turtle’s which displays both the date and day.
The Seiko Turtle shares similar qualities with the Seiko Sumo in the markers on the dial. These markers typically come in different colors depending on the model.

Also, just like you have it on the Seiko Sumo, the minute and second markers are on an outer ring that slide down and join to the dial at a nice angle. The hour makers, on the other hand, stay on the face of the dial.  

The 12 O’ clock, 6 O’ clock, and 9 O’ clock markers have rhomboid markers while the other hours, save the 3 O’ clock marker are circular in shape. The 3 O’ clock position is where the day/date complication is displayed.  

Besides the hour markers on the dials, there are also other typical Seiko signatures on the dial. The 12 O’ clock carries the brand name. Also, at the 6 O’ clock position, you find the signatures “Automatic,” and “DIVER”S 200m.” In addition, there’s a really cool “X” sign also at the 6 O’ clock which is representative of the Prospex line which the Seiko Turtle belongs to.  

You also find these signatures on the Seiko Sumo as well, lest we forget.

Unidirectional Rotating Bezels

Which has better unidirectional bezels – Seiko Sumo vs Turtle?

The Seiko Turtle has a better looking unidirectional rotating bezels than the Seiko Sumo. Seiko Turtle favors bi-colored bezels a lot. And this helps to improve their aesthetic look.

When it comes to their functionality, there isn’t any difference between Seiko Sumo and Turtle. Just like in all standard dive watches, Seiko Sumo and Turtle watches follow the diver’s watch standard. The watches come with unidirectional bezels.

As a standard, the bezels of the Seiko Sumo and Turtle are unidirectional and only rotate in a counter-clockwise direction. For the purpose of reassurance, each turn of the bezel returns with the satisfaction of a click.

Besides that, the bezels also come in polished stainless steel. So, typically, the Seiko Sumo and Turtle watches are nice watches with attractive bezels.

And for added functionality, these bezels also come with a ribbed outer surface. This improves your grip especially since you’ll be using this in wet conditions.

Furthermore, the main marker on the Seiko Sumo and Turtle is a large arrow just like on most dive watches. But that’s just the main marker. There are also minute/second and hour markers like you have them on the dial.

The minutes and seconds here are represented by small dots which turn to tick lines in the 5th minute/second and counting further in 5’s (i.e. 5, 10, 15,…,60). The hours though are represented by Arabic numerals.

Why are the bezels unidirectional?

Bezels are unidirectional because they help guide the diver in the case of unintentional alteration of the bezel movement. Professional divers understand that underwater, anything could happen.

For instance, say you knock something mistakenly, or your watch tugs on something. This could cause a rotation of your bezel which could be disastrous. You could read the time wrong and end up spending a longer time underwater. This is the reason watchmakers prefer to opt for unidirectional bezels.

Video: How to Use a Dive Watch Bezel

In this video, you get to see how to use a dive watch bezel.

Shatter-Proof Hardlex Crystal

Though these are about sub-$1000 watches, the crystals on the Seiko Sumo and Turtle are both the same as the ones on the lower-priced SKX line. So, it’s the same shatter-proof Hardlex crystal on the two watches. Is that the best crystal your watch could get? Well, if you read our review on the Seiko SKX007 vs SKX009 (click here to read it), you’d find that the answer to this is no.

So, why the wide price gap? Well, the fact that Seiko didn’t change the crystal doesn’t mean that other things weren’t improved on. There are several improvements made to these watches. However, you need to keep in mind that at a price of roughly less than $1000, these are still regarded as cheap watches. Compromises should be expected here and there.

See also  Seiko 5 vs Orient Bambino – Extensive Comparison

But yeah, in terms of improvement on the SKX models, these watches have a more sophisticated movement. Plus, they also have a much better bracelet than the SKX watches.

And it’s not like Hardlex is so bad. Yes, the crystal smudges a bit too easily but it is also quite tough. It doesn’t crack too easily, although if you’re determined to crack it, you just might succeed. However, if you’re just talking about those incidental impacts that come from everyday use, this crystal is solid.


What are the differences between the crown in Seiko Sumo and Turtle?

There are no differences that can be seen in the crowns of Seiko Sumo and Turtle. Both watches have their crowns at the 4 O’clock position, just like most Seiko watches. In fact, the crowns on these two watches are pretty much the same thing.

The crowns in both watches are also quite large. However, they are protected by crown guards which make the crown look less intimidating.

Plus, to ensure that you have a firm grip when making your adjustments, these crowns come with a fine-toothed edge. This ensures that your fingers don’t slip. This makes time setting easier.

To set time and date using the crown is pretty intuitive too. We explained the process in our Seiko SKX007 vs SKX009 review so you could check that out.

Stainless Steel Bracelet

How does the stainless steel bracelet of the Seiko Sumo compare to that of Turtle?

The stainless steel bracelets on the Seiko Sumo and Turtle are pretty much the same. In fact, it’s not just the Seiko Sumo and Turtle, all watches in the Prospex line and within this price range have pretty much the same type of bracelet.

The bracelet features a deployment clasp for closure with the signature “Seiko” on the flap. Of course, this also adds to the beauty of the watch as well.

Besides the clasp, these bracelets also feature a micro-adjustment which makes it possible to set the bracelet to your wrist size. We doubt any form of adjustment would make either watch usable by people with slender wrists, though.

Now, both available models of the Seiko Sumo come with stainless steel bracelets. However, not all models of the Seiko Turtle come with a stainless bracelet. The ones with a stainless steel bracelet are listed below:

  1. Seiko Turtle SRP773
  2. Seiko Turtle SRP775
  3. Seiko Turtle SRPA21 PADI edition
  4. Seiko Turtle SRPC65.

NB: The Seiko Turtle’s bracelet is a bit wider than that of the Seiko Sumo by about 2 millimeters. While the Seiko Turtle’s measures at 22 millimeters, the Seiko Sumo measures at 20.

Automatic Movement

Do Seiko Sumo and Turtle share the same type of movement?

Both Seiko Sumo and Turtle watches use an automatic movement. However, although they are both automatic, the movements in the Seiko Sumo and Turtle are different.

The Seiko Sumo uses the 6R15 automatic movement while the Seiko Turtle uses the 4R36 movement.

With both movements, you get 21,600 beats per hour which amounts to 6 beats per second. This is important for accuracy, although the 6R15 movement is more accurate than the 4R36 in theory. In practice though, we find both movements quite accurate and many users agree.

Also, these movements come with manual winding. Meaning that you can crank them up yourself when the power eventually goes out.

Another difference between both movements is their power reserve. This is another area where the 6R15, found in Seiko Sumo, does better. It comes with about 50 hours of power reserve which is about 9 hours higher than that of the 4R36 found in Turtle.

In practice, this means that once your watch is fully charged, it can last up to two days without needing a recharge. But, you want to keep in mind that as the charge level begins to drop, the time on the watch becomes more inaccurate.

Regulating your watch using the manual winder is quite easy and you can also do that at your local watch shop.

Although it’s easy to regulate the watch yourself, we still advise you to get a professional to do it. This is so that you don’t compromise the ISO certified standards on the back of the case. For instance, if you mess up the screw lock of the back case, you could damage the water-resistant ability of the watch.

Lastly, both movements are hackable which means that the second hand in both watches also stops moving once the crown is pulled fully out to set the time.

And yeah, one final difference between both movements is that the 6R15 only comes with a day display. The 4R36, on the other hand, comes with the day/date complication.

Video: How to Regulate an Automatic Wristwatch

This video shows how you can regulate your automatic watch yourself.

Water Resistance

Which has the better water-resistant ability: Seiko Sumo or Turtle?

Being dive watches, the Seiko Sumo and Turtle are both water-resistant. Also, as per ISO standards, they are water-resistant down to 200 meters underwater. In fact, it comes with the signature on each watch – the “DIVER’S 200 m,”.

Because of this feature, it is important to be careful if you ever have to tamper with the back of your watch. If you don’t do it properly, it could affect the water-resistance ability of the watch. This, of course, as you know, is bad news for your watch.

Dive Ready Watches

How good are Seiko Sumo and Turtle as dive ready watches?

Both Seiko Sumo and Turtle watches meet the ISO 6425 standards, so they make great dive watches. And not just that, you also have the peace of mind knowing that your watch meets the standards making them safe to use.

You can confirm that from their unidirectional bezels, luminescent hands, and water-resistant cases.

For further reading, you can check out the review we made on the Seiko SKX007 vs SKX009 to find out what those ISO 6425 standards are.

Seiko Sumo Vs Turtle – Features Unique To Each Watch

Seiko Sumo Vs Turtle – Features Unique To The Seiko Sumo

Seiko Sumo Hands

What are the features of a Seiko Sumo’s hands?

The hands on a Seiko Sumo watch are usually thicker than hands on the Seiko Turtle. For some, this might look more stylish than the hands on the Seiko Turtle.

As the hands head closer to their points, they tend to taper a bit. The Seiko Sumo does not have the Turtle’s arrow-like minute hand or its needle-like point.

Also, the second hands of the Seiko Sumo vs Turtle are quite different as well. The Seiko Sumo features a really thin second hand, and close to the tip of the second hand is a rhomboid-shaped marker.

Seiko Sumo Vs Turtle – Features Unique To The Seiko Turtle

Seiko Turtle Hands

What are the features of a Seiko Turtle’s hands?

The hour hand on the Seiko Turtle comes in the shape of a syringe. And it also features a needle-like tip at the end of the syringe-like hand.

Next, the minute hand. This one looks like an arrow but also features a needle pointer protruding from the tip of the hand.

And then the second hand. It is slim and, unlike that of the Seiko Sumo, is bi-colored. The counterbalance part of the second hand is colored black while that of the pointer side comes in white. Helps with the focus of the wearer.

Silicone Rubber Strap Option

Do both Seiko Sumo and Turtle have an option for rubber hands?

The Seiko Turtle has options for a rubber strap if that’s what you prefer. However, Seiko Sumo does not have the option of a rubber hand.

Rubber straps are better preferred than stainless steel bracelets for diving for obvious reasons. They don’t get wet. Plus they are also super easy to clean.

The Seiko Turtle models that use the silicone rubber strap are:

  1. Seiko Turtle SRP777,
  2. Seiko Turtle SRP779
  3. Seiko Turtle SRPC44

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Seiko Sumo Vs Turtle – Unique Pros

Seiko Sumo Vs Turtle – Pros Unique To The Seiko Sumo

The pros unique to the Seiko Sumo are:

• The case is slightly smaller than that of the Seiko Turtle.
• 6R15 movement is slightly more complicated than the 4R36. It has a higher power reserve time, features a day/date complication, and some may say greater accuracy.
• Crown has a better grip than the one on the Seiko Turtle.

Seiko Sumo Vs Turtle – Pros Unique To The Seiko Turtle

The pros unique to the Seiko Turtle are:

• There are a lot more models of the Seiko Turtle available than the Seiko Sumo. So, you get more options with the Seiko Turtle.
• You also get the silicone rubber strap option with the Seiko Turtle unlike with the Seiko Sumo that only features the stainless steel bracelet.
• More dial and bezel colors to choose from as well.

Seiko Sumo Vs Turtle – Unique Cons

Seiko Sumo Vs Turtle – Cons Unique To The Seiko Sumo

  • There aren’t as many models, dial colors, or bezel colors to choose from.
  • No rubber strap option to choose from, just stainless steel bracelets.

Seiko Sumo Vs Turtle – Cons Unique To The Seiko Turtle

  • It’s larger than the Seiko Sumo.
  • Movement isn’t as complicated as the 4R36. Power reserve of the Seiko Turtle is lower at 41 hours vs the 50 hours of the Seiko Sumo.

Seiko Sumo Vs Turtle – Common Pros

Seiko Sumo

Seiko Turtle

The Seiko Sumo is quite large but it’s great that the watch also comes with an adjustment feature. This means you’ll be able to set the watch to fit your wrist. The only problem is it still won’t work if your hands are slim. Also applies to the Turtle.
The cases of the Seiko Sumo look good with their brushed and polished effects. They aren’t as large as the Seiko Turtle’s though. The peculiar shape of the Seiko Turtle makes it attractive to some buyers. They also come with the brushed and polished effects as well which is nice.
This watch comes with automatic movement which is great. An automatic movement has a lot of advantages but the greatest is that you don’t have to wind your watch manually. As long as you’re wearing the watch and swinging your arm, the watch winds automatically. Also applies. Plus, the automatic movement of the Seiko Turtle comes with the day/date complication.
Watch is totally hackable. You’ll be able to set the time precisely down to the second since the second hand stops once the crown is full out. Also applies.
Meets the ISO 6425 standards which makes the watch a fantastic dive watch you can depend on. Same goes for the Seiko Turtle.
With LumiBrite, the hands of these watch are bright enough to be seen in pitch darkness. This is a part of the ISO 6425 standards which the Seiko Sumo meets. Also applies to the Seiko Turtle.
This watch is water-resistant down to 200 meters underwater. Same here.
For all the features you get with this watch, we consider this watch a pretty affordable one. The same also applies to the Seiko Turtle. It’s pretty affordable.
Get the Seiko Sumo here!   Get the Seiko Turtle here!


Seiko Sumo Vs Turtle – Common Cons

Seiko Sumo

Seiko Turtle

The Seiko Sumo comes with a great crystal. However, it still has its smudging problem. It is scratch-resistant but if you try hard enough, you could probably crack it. Also applies.
This is a pretty large watch which makes it a little unattractive for some buyers, especially those with smaller wrists. Same here.

Seiko Sumo Vs Turtle – General Feeling Among Users

Seiko Sumo Seiko Turtle
We think most people who bought the Seiko Sumo were impressed by the quality of the watch. For one, they found the lume to be quite outstanding and brilliant. Plus the fact that the watch meets the ISO standards made a lot of users happy.  

Still there were some people though who thought that the SKX007 gave better value than the Seiko Sumo. This wasn’t a popular opinion, however, as more people felt the upgrade was worth it.    

Now, there were two complaints that seemed to be fairly constant as customers commented on the Seiko Sumo.  

First off is the chapter ring. Apparently, many customers received their watch with the chapter ring misaligned. So, rather than sit dead-center, it came off slightly off. For a watch selling at about half a thousand bucks, many weren’t pleased.  

Next was the bracelet. There were a number of replacements that’s for sure. In some cases, the quality wasn’t good enough for some users. And in other cases, there were complaints that the band was too tiny for the large watch at 20 millimeters.  

But even with all the complaints, there was no scarcity of 5-star reviews. It’s obvious that these few hiccups weren’t enough to dissuade people from owning this or from giving it their highest rating.
The Seiko Turtle and Sumo seem to share the same troubles. It seems like Seiko hasn’t quite gotten its chapter alignment right. It might have been a small case of poor quality control with the Sumo, but it’s spreading across models now and we’ve got questions. What’s up, Seiko?  

Anyway, even at that, we still found that many customers were pleased with their watches for the most part. In fact, we found people who simply didn’t want to take their watches off. Further proof of its comfortable style. In contrast, the Seiko Sumo had one complaint of the bracelet snagging clothing and even skin.  

Anyway, that said, the interesting shape of the watch made it attractive to watch enthusiasts. There were people who were just getting the watch for the purpose of owning it, not necessarily wearing it, kinda like a collector’s item.  

Now, although a few people commented on the size of the watch, it wasn’t a very common complaint. Apparently, most buyers already knew what they were up against beforehand. So, it wasn’t a big deal.  

All in all, the Seiko Turtle is a great watch and most agree.

Seiko Sumo Vs Turtle – Wrapping It Up

In our opinion, the Seiko Sumo and Turtle are really similar watches and one is probably only better than the other in terms of individual preference. What gives the Seiko Sumo an advantage over the Seiko Turtle is not large enough to be a deal-breaker for us. Plus, you can live without those small plusses.

See also  Seiko SKX007 vs SKX013 – Which Should You Get?

So, our opinion? Feel free to get what you like. Both are great diver’s watches well worth their price.

Seiko Sumo vs Turtle – FAQs

What Does Prospex Mean?

The full meaning of prospex is ‘Professional Specifications’. This is Seiko’s response to the demand of various professionals. There are professional bodies that need certain specifications to be met in the type of watch they use. This is most seen among sportsmen. These specifications are meant to contribute, in some ways, to the success of their sport. Examples of professionals with such expectations are divers and swimmers.

As a result of this, Seiko has put together a lot of resources to meet a certain standard. The watches in the prospex line are high end watches. Seiko fans and professionals see this line of watches as the ultimate tool watch.   

What do Seiko model numbers mean?

The Seiko model numbers are used to indicate the period of production of the watch and its unique number. The model number consists of 6 digits. And these 6 digits represent different things. The first digit represents the year of production, the next digit is the month of production, while the last 4 digits represent a unique production number.

The numbering for the month is listed from 1-9. This represents the months of January to September. The month of October is represented with ‘O’, November with ‘N’, and December with ‘D’. If the model number of a watch is 642012, it means the watch was produced in April 1976 and the production number is 2012.

How do I know if my Seiko watch is real?

To know if your Seiko watch is real, look out for the following:

  1. All modern Seiko watches come with a 6-digit serial/model number. All watches produced by Seiko after 1970 come with the 6-digit model number. Pre-1970 watches come with 7 digits.
  2. The Seiko movement and model number are engraved on the caseback of the watches. The numbers are separated by a dash with 4 digits on each side. The first four digits represent the movement calibre number while the second set of four digits represents the model number.
  3. Every Seiko watch comes with the Seiko logo written on the watch face (dial). 

Is Grand Seiko as good as Rolex?

Grand Seiko is better than Rolex. When you talk about their features and movement, the Grand Seiko trumps Rolex completely. The only thing that Rolex has going for it is that it is a more prestigious brand than Seiko. 

No watchmaker has produced as many automatic chronograph movements as Seiko/Grand has made. Rolex has only one automatic chronograph movement. Moreover, Rolex watches are sports watches not luxury/elegant watches. Although they seem to enjoy that privilege now, the Grand Seiko is a known luxury watch and it meets the criteria to be regarded as such. The Grand Seiko is the best horological watch you can find today.

Why does my Seiko automatic stop?

There are various reasons why your Seiko automatic watch may stop. Seiko automatic watches are made to be self-winding watches. The self-winding mechanism is powered by the movement of your wrist. However, if the watch does not receive enough swinging from your hand, the battery may not be fully charged.

Another reason for your Seiko automatic to stop is that you may not have worn your watch for up to 2 days at a stretch. Most Seiko watches have a power reserve ranging from 40 hours to 50 hours. Therefore, if the watch does not receive charging for up to 2 days or more, the battery will run out.

Do Seiko automatic watches need servicing?

Seiko automatic watches need to be serviced. But the frequency of servicing depends on various considerations. Such considerations are the climate and the individual care given to the watch. Generally, a Seiko automatic watch should be serviced every 3 years.

To be sure that you get the best service for your watch, take your watch to an Authorized Seiko Service Center. If you fail to service your watch at the right time, the moving parts may become worn out. Also, the oil that lubricates the moving parts may lose its viscosity. This can make your watch become inaccurate or stop outrightly.