Seiko watches are extremely popular with collectors. Even the humble SKX007 is rising in value as fewer OEM models are out there in new condition. The Japanese watchmaker has a long history of making amazing dive watches for professionals and enthusiasts.

While the Japanese brand has long been known for creating watches with case shapes and features that make them distinctive, we are here to talk about the Seiko Turtle which is a highly functional tool watch that is still available at a very reasonable price. 


Source: Carousell


Ranging from the earliest 6306 references to the modern re-launched SRP series in the Prospex line, the Turtle has shown its desirability for anyone who loved classic dive watch designs. 

The Turtle is a cushion case dive watch that most people who know Seiko already like. It is one of the great examples of a timepiece that’s odd enough to not only stand out but also be embraced over the course of decades. Today, the SRP777, or all black standard Turtle, is likely the best choice for anyone who wants to mod a Seiko diver. Let’s jump into why this model is so popular! 

Short History of The Seiko Turtle

The story of the Turtle begins in 1976 with a model released for the Japanese market, named the 6306-7000/1. Powered by Seiko’s 6306A caliber, the watch had a 60-click bezel encircling a black dial with oversized lume dots in a mix of circular and ornate shapes. 


Source: Reddit


With a depth rating of 150 meters, this first ever version of the Turtle could easily meet the needs of a recreational diver or anyone else who desired a daily wear timepiece. Another feature that was treasured by its fans was the English/Kanji day-date wheel, which was only made for the Japanese domestic market. 

The international version of the 6306-7000/1, called the 6309-7040/9 (we know, not very catchy) is essentially identical to its brother, with the exception of the day and date wheels. 

The Turtle's nickname comes from the oblong, softly curving appearance which looks like a turtle shell when viewed from above. The sloping lines also make the watch easy to wear under a shirt sleeve. 


Source: H2 Hub


Because of their extraordinary durability, the two early Turtle watch models have become a go-to timepiece throughout much of the 1980s. As a popular cultural symbol, it most famously appears in James Cameron’s ​1989 film, The Abyss. A 6309 was worn by actor Ed Harris throughout the film.


Source: Hub City Vintage


The early ’80s also saw the appearance of what was known to collectors as the Slim Turtle, with a sharper and more angular case, and overall trimmer profile. Although quickly disappearing after just a few years, the watch represents the first glimmer of what would later become the SKX007, which many consider to be the ultimate tool diver. In addition, the caliber 6309 movement is the stuff of legend. 

Many collectors have reportedly purchased Seiko Turtle watches that are over 30 years old but still functioning impeccably. In 2016, the Japanese brand relaunched the Turtle and received great acclaim. 

As a part of the Prospex series which is known for its technically-advanced, high-grade functional watches, the updated version of the original 6309 has immediately attracted the attention of the watch enthusiast community. 


Source: Omega Forums


The modern counterparts of the Seiko Turtle such as the SRP777 (Black), SRP775 (Black/Gold), SRP779 (Pepsi Bezel), and SRP773 (Blue Bezel), were all instant hits at launch.

So, what makes the Seiko Prospex SRP Turtle series like the SRP777 such cool timepieces among watch enthusiasts?

The SRP777 vs The SKX007

With the Prospex SRP series, Seiko lovers or Turtle fans can strap on a piece of history that still feels modern. Designed with a case size of 45mm, the SRP777 are only about half a millimeter larger than their vintage inspirations. On the other hand, the watch featured handsets and dial elements nearly identical to those of the 6309.


Source: Worn and Wound


The notable differences are technical. The SRP777 replaces the well-known 150 meters of water resistance above the iconic Suwa logo with the Prospex logo and the upgraded water resistance rating of 200 meters.

It seems natural to see that the SRP777 and the SKX007 are both must buy Seiko divers. But today the SRP777 gives us a much better deal when looking at larger sized diver watches. 

Of course, both are well-made ISO-rated dive watches with an in-house movement, made in the image of a modern classic. Although SRP777 Parts are available, many modders opt to use aftermarket parts instead - much like the SKX007


Source: @nicolaswatches on IG


Although relatively large at 45mm, the square cushion-case design and squat lugs of the SRP777 make it wear comfortably on most wrists. Unlike other large dive-watches that may feel heavy and unbalanced, the SRP777 defies its size on the wrist to bring an incredibly comfortable wearing experience. 

The SRP777 and the SKX007 have a similar design, but the SRP777 represents an upgrade in almost every technical department.


Source: Worn and Wound


One of the biggest quality upgrades was in the movement that powers the SRP777. The new Turtle uses Seiko’s in-house caliber 4R36 movement which has 25 jewels and a beat rate of 21,600bph. Unlike the 7S26 of the SKX007, this new movement is hackable and hand-winds.

Although both movements are incredible values, having the ability to stop the second hand while setting the time makes a huge difference for overall accuracy and gives it a much higher-end feel. The lugs are drilled which is another great feature that you won’t find in the SKX007, which makes strap changes a breeze. 

Wrap Up

When Seiko decided to reissue the fan-favorite turtle dive watch after nearly 3 decades, these watches became an instant hit and were sold out for months. In addition to owning an original Seiko SRP777 timepiece, you can also use the extensive selection of parts we make here at namokiMODS to improve it.

If you want to skip buying a Seiko SRP777 and the teardown, we offer a great SRP style Turtle Case, and a Rubber Strap to match. If you want to create Seiko mod watches, we are here to help with some of the best watch mod parts in the market. 

Whether you are looking for Seiko spare parts, or Watch spare parts, make namokiMODS your first choice when you are looking for top quality parts that will deliver years of service. Seiko Mod Watches are hot, and your custom SRP777 is sure to be a great project! 

May 30, 2022 — Jeremiah A

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