Movement

Beating away inside the SRP77x series is the Seiko 4r36 caliber movement. The 4r36 hacks and hand winds, has 25 jewels, a beat rate of 21,600bph, and 41 hours of power reserve. In other words, it’s a solid movement from Seiko–a step above the 7s26 but a notch below the 6r15, which is Seiko’s competitor to ETA’s 2824. Some might bemoan the perceived downgrade, but the 4r36 is a workhorse built up from the ever-reliable 7s26. It can also be adjusted to achieve great accuracy. The main structural difference between the 4r36 and the 6r15 is that the latter has a mainspring and balance spring made from Seiko’s SPRON material, which better handles positional and temperature variance. I haven’t timed either of these watches, but I haven’t noticed any major timekeeping fluctuation that would make me think the movement is underperforming. Plus, if it helped keep the price down then I am more than okay with the use of this caliber.

Straps and Wearability

The SRP77x series comes with two strap options–either a metal bracelet or a black silicone strap. The bracelet is 22mm at the end links (solid) and it tapers down to 20mm at the clasp. It has four points for micro-adjustment, a diver’s extension, and the links are connected using a pin-collar retaining system. It’s essentially an oyster style bracelet, though the inner edges of the outer links are polished while the rest of the bracelet is brushed. It’s a good looking bracelet and it feels solid, though the clasp is probably the only weak point, but Seiko isn’t really known for their clasps. I do find that the bracelet adds a significant amount of weight to the watch head, which is already weighty on its own. My personal preference is the OEM silicone strap. The silicone strap is smooth and pliable and much nicer than the z22 rubber straps that come paired with the 007, which I find to be too rigid. The strap also features a new buckle design and a metal keeper, both of which are well finished with polished sides and brushed surfaces.

Even though the SRP77x is a dive watch, I find that it pairs well with a wide variety of straps. Naturally, I’ve tried it on a nylon and leather mil strap. I’ve also had it on a Di-Modell pilot’s band, as well as one of our vintage-inspired Model 2 straps in shell cordovan. Admittedly, I’m a desk diver so I have no issue pairing leather with a dive watch. At the end of the day, it’s about what looks good and I think this watch is a bit of a chameleon in that regard.

Conclusion

Seiko got this one right. So many brands today rely on their archives for their current releases, and many unfortunately screw it up. Here, Seiko brought back the 6309 the right way, modernizing the build but still keeping the general feel and aesthetic of the original intact. At retail, the Seiko Prospex SRP777 / SRP775 is a great buy, and probably one of the best sub-$500 divers on the market. Heck, it even fares well against most sub-$1000 divers. Not to harp on my 50 Atmos, but I put the two side-by-side and saw little reason to shell out the extra cash for the Squale (except, of course, a preference of design). With a street price that seems to be hovering around the $350 mark, the SRP77x is a no-brainer. For those looking at the 007 as an affordable diver, I would argue for spending more to get the SRP. The look and feel of this series just comes across as being in a class above the 007, and I personally find the aesthetic far more pleasing. All in all, it’s a great release by Seiko, and now I’m left wondering what else they have in store.

big thanks to 10:25 Vintage x analog/shift for lending us the 6309