After we were among the first to show you the new Seiko SRP777, SRP775, SRP779 and SRP73 in this post, I couldn’t wait to get my hands on them and see if they are just as good as the original Seiko 6309. Michael wrote a wonderful review for our #tbt feature on the Seiko 6309 here and he concluded with “It’s a cornerstone piece for any collection and it looks good in most settings. It’s also one of those watches that tend to get the respectful nod from those wearing watches 10-20 times more expensive.”.

He also made me enthusiastic about the Seiko 6309 and found myself buying one from a Seiko collector in the United Kingdom. All parts were original and the watch was in good overall condition. I had it serviced and regulated by Seiko in The Netherlands nevertheless, and I find myself wearing it relatively often in my – what I’d like to call – rotation programme. I paid $320 USD including shipping, and as Michael stated in his article, that is a crazy amount of bang for the buck.

But what if you don’t like to buy vintage watches? You either can’t find one with original parts (dial and hands replacements are very common) or don’t want to risk ending up with a Seiko 6309 with a completely worn out movement (not many people had their relatively cheap Seiko 6309 serviced in 30-40 years). The new Seiko SRP777 and its derivatives might be an excellent alternative for the Seiko “Turtle” 6309.

Seiko SRP777

The new Seiko SRP777 – part of Seiko’s Prospex collection

Seiko SRP777 Prospex

Before I take a closer look at both watches, let’s zoom in on the new Seiko SRP777 model first. Perhaps I should start with the positioning of this watch in the Seiko collection. It is not a direct descendant of the Seiko 6309, that would be the famous Seiko SKX007. The Seiko SKX007 (retails at €299 Euro here in Europe) belongs to the Seiko 5 collection, based on its movement: caliber 7S26. The SRP777, SRP773, SRP775 etc. are part of the Prospex (“Professional specifications”) collection and have movement caliber 4R36. This movement can also be found in the current Seiko Monster collection for example. It is an automatic (but also manually “windable”) 25-jewel, 21,600vph, hacking movement with a day and date feature. The movement has a power reserve of 41 hours minimum when fully wound.

You will find the Prospex logo “X” on the dial of the Seiko SRP777, as shown below, to indicate that this watch is part of that ‘professional’ collection. The applied indices are lumed and perform very well in low-light conditions. The hands are those typical Seiko divers hands, but look awesome and are very legible. The printing on the dial is of good quality and razor sharp. The bezel on the black Seiko SRP777 was a bit ‘tough’ but fine on the SRP773 and SRP775 reference. I think I might have been unlucky with this particular watch.

Seiko SRP777

Prospex logo on the dial of the Seiko SRP777

The “professional” part is mainly within the water resistance of this watch, 200 meters. The Seiko SRP777 has Seiko’s famous Hardlex mineral crystal, that some consider as negative, but I have to say that none of my Seiko watches with Hardlex crystals got scratched up till now. The case is 44.3mm in diameter and 13.4mm thick, so by no means a small watch. However, due to its shape, it is a very wearable watch. It has a screw-down crown and the case back also is screw-in, to ensure water resistance.

I received the Seiko SRP773 and SRP775 as well from Seiko, but like to focus on the Seiko SRP777. To be honest, I would settle for the Seiko SRP777 in any case, because that silicon strap that comes with it is incredibly comfortable. It is nice and soft and makes me wonder why I had to put down €180 Euro for a silicon strap (from the SBDX013) for my vintage Seiko Tuna 6159-7010. If I would have known this, I would have ordered the 22mm strap for the Seiko SRP777 for my Tuna 6159-7010.

The SRP773 and SRP775 models come with a metal bracelet, as can be seen below. I didn’t take the time to have them resized (they come with enough links to fit huge wrists, which is a good thing), but the bracelet do what they should do and have a flip-lock on the clasp for safety. Design-wise they are very similar to the bracelets that are already being used on some of the Seiko Prospex models.

Seiko SRP777 SRP773 SRP775

The clasp opened & closed

Again, even though the quality is spot-on with respect to the bracelet of the SRP773 and SRP775 references, I much prefer the silicon strap of the Seiko SRP777. Perhaps also because it is also much closer to the original reference 6309 watch in this configuration.

With a retail of €395 Euro for the Seiko SRP777 and €35 Euros more for the SRP773 and SRP775 with metal bracelets, this watch is a no-brainer if you need a rock-solid water resistant mechanical watch. I would prefer it over the Seiko SKX007 to be honest (although official retail is relatively high for it in Europe compared to elsewhere), due to the strap (or bracelet, in this case) and the hacking movement caliber 4R36. However, the design of the SKX007 (and SKX009) case is a bit more easy-going and perhaps more attractive if you don’t fancy vintage looking diver watches.

Seiko SRP777 SRP773

Seiko SRP773K1

Seiko SRP777 versus 6309

Battle of the turtles, although Michael Stockton learned me that I should refer to these models as turtle. As said, I wear my Seiko 6309 quite regularly and it performs nicely. The watch was going fast at first, but it seems that after the service at Seiko, it is going much better. Seiko told me that the movement in my 6309 needed some replacement parts as they were totally worn out. That is a bit of an issue with these old Seiko watches. It is a bit like Rolex, how many people do you know that are not specifically into watches and had their Rolexes serviced in their +25 years of ownership? The same – or perhaps even worse – for Seiko I think. People bought a Seiko diver decades ago and never serviced it, perhaps also because service cost would be relatively high for these watches compared to the price at purchase. That’s is not entirely true, as I’ve been told that Seiko only charges a very low amount to retailers for service, it is the retailer that some times multiply this price by 3 or 4 to their customers. Perhaps to earn a quick buck on service or repair, but also perhaps to encourage them to just buy a new Seiko from the shelf.

Getting parts of vintage pieces becomes worse these days, although I can’t imagine it would be too hard to find the right parts for the Seiko 6309 watch. eBay and Seiko forums have enough to offer if you monitor it closely, but this is something not everyone likes to do (or don’t have enough time on their hands to do so). In that case, the choice for a SRP777 or one of its cousins might be an obvious choice. Especially for the price, you don’t have to make tough decisions here. It is just about preference. However, I can only imagine the new caliber 4R36 is much more accurate (and besides, hacking and can also be wound by turning the crown) than the old caliber 6300-series.

Seiko SRP777 versus Seiko 6309

Seiko SRP777 versus Seiko 6309

As you can see above, my 6309-7049 is on the right and the new Seiko SRP777 is on the left. Besides the scars and marks from wear on the 6309, these watches are very much “the same” at first glance. Let’s just say that my wife wouldn’t spot the differences (and she didn’t). Even up to the printing on the dial, there are only few differences. Of course, the new Seiko SRP777 has some different indicators including the Prospex logo and the “Diver’s 200m” notification where the old 6309 just talks about being an automatic and 150m “water resist”. The Suwa logo just above the hour marker at 6 o’clock indicates Japanese production. With regards to the bezel, the pearl in the old 6309 bezel is a bit larger but up to the printing it is quite similar. As you can see, the bezel on my 6309 has seen some wear, but nothing to worry about. It still functions properly.

The lume is clearly different on the new Seiko SRP777 and does a very nice job, where the old lume on the 6309 is dead. Probably for a long time already.

Seiko SRP777 vs Seiko 6309

Differences in profile – Seiko SRP777 vs 6309

The bezel design is a bit different when looking at it from the side, the ‘hob nail’ is a bit finer on the old 6309 reference. The crown is still un-signed and although some people prefer a signed crown and see this is as a more ‘luxury’ detail, I actually like the fact that Seiko holds on to these things. Their design department did a very good job. The new Seiko SRP777 has lug holes, which makes it much easier to remove a strap (or bracelet). The dimensions of both references are almost identical (44mm x 14mm for the 6309), even there Seiko did a wonderful job not getting distracted by any ‘hypes’ or trends (smaller or larger), they just perfectly re-did the 6309.

Seiko SRP777 vs Seiko 6309

Caseback comparison

Seiko – of course – used the Tsunami medallion for the stainless steel screw-down caseback. Then there’s the Prospex logo again, a serial number and the caliber number of the movement. The old caseback is relatively similar in sharing specifications. As you can see the crown construction is a bit different and, from what I guess by looking at it, the new case is better prevented from water and dust entering via the crown.

Seiko SRP777 versus Seiko 6309

Straps and buckles

Where my old Seiko 6309 has this 22mm GLA45 type of strap with perforated keeper and simple brushed buckle, the new Seiko SRP777 comes with a silicon strap, nicely brushed keeper and a beautiful Seiko signed V-shaped buckle that reminds me a bit of those Pre-Vendome Panerai buckles, but smaller. I already wrote how much I like the new silicon strap so I will refrain from repeating myself too often here. The old straps are OK, but feel kinda plastic and while I have one new (New Old Stock) reference GL83 strap in its original packaging, it is damaged over time (perhaps a bit too long in the direct sunlight or something) and became unusable, it is just no comparison to the new silicon strap.

When comparing new vs old here, I have to say that Seiko did an excellent job respecting the design of the original Seiko reference 6039-7049 and its dimensions. The finish on the caseback of the Seiko SRP777 is nicer and of course the movement is just a modern well-performing caliber. Add a luminous set of hands and dial and the much appraised silicon strap and you have a winner. In that respect, it is only ‘nostalgic’ that should make you want a 6309 over a SRP777 as the price is – today – more or less the same. The risk of a worn out movement would be – for me – the reason to purchase the new Seiko SRP777 alone, to be honest.

Are their any wrongs regarding the Seiko SRP777 and the other SRP77x references? Some might complain about an un-signed crown or perhaps the Prospex logo on the dial, but there is actually not one reason not to buy this watch if you are looking for a modern vintage-looking diver under €500 Euro.

More information via Seiko Watches. The Dutch go here.