Seiko Padi SRPA21 vs SUN065: A Seiko Dive Watch Comparison

Seiko is one of the most coveted brands in terms of excellent diving watches, and one its most well-known models is the Seiko Padi. The successful collaboration between Seiko and the Professional Association of Diving Instructors (PADI) has resulted in the release of two PADI Special Edition dive watches: the SRPA21 and SUN065. 

Both the Seiko PADI SRPA21 and SUN065 are high-end dive tools that are equipped with all the incredible features you can expect from a reliable dive watch. Without further ado, let us find out more about what the Seiko PADI SRPA21 and SUN065 can do, along with how they compare against each other. 

Seiko Padi: An Overview 

In 2016, the Japanese watchmaker Seiko and the world’s largest diving network, PADI, proudly announced the beginning of their partnership. Both Seiko and PADI share an enthusiasm for underwater sports and ocean conservation. This strong collaboration resulted in the release of two Seiko PADI Special Edition divers: the SRPA21 and the SUN065.

Designed as the ideal tool for diving adventures, the Seiko PADI SRPA21 and SUN065 are robust, durable dive watches that have been tested for professional use. These top-tier timepieces show off a classic dive watch appearance and are packed with essential diving features, which we will now take a closer look at. 

Anatomy of the Seiko Padi SRPA21 and SUN065

Seiko Padi SRPA21

The Seiko Padi SRPA21 is a highly-recognisable dive piece, with its striking Pepsi bezel and sturdy build. This watch comes in a 45mm cushion-shaped case made of stainless steel, with a cleanly brushed shroud that also serves to guard the watch’s crown. The crown itself is placed at 4 o’clock. Placing the crown at this angle ensures that it will not dig into the skin of the wearer’s wrist, giving users a more comfortable wearing experience. 

Affixed to the top of the watch case is a unidirectional elapsed time scale bezel in handsome Pepsi colours. A luminous pip can be found at 12 o’clock, which helps illuminate the watch face in the dark. 

The dial of this watch shows off a rich sunburst blue finish, which goes well with the Pepsi bezel. It is furnished with thick arrow hands and oversized hour markers, all of which are coated in the brand’s own LumiBrite material. This allows for optimal legibility at all times. A compact day-date display can also be found at 3 o’clock.

Driving this watch is the Seiko Calibre 4R36. This is a reliable self-winding movement that is held together by 24 jewels and beats at 21,600 vibrtions per hour. It also delivers a standard 41-hour power reserve and has the ability to withstand magnetic fields of up to 4,800 A/m. 

Completing this watch’s sleek look is a polished three-link bracelet that is also made out of stainless steel. This bracelet is equipped with a double locking push-button clasp. It keeps the watch securely fastened to your wrist, and can also be easily slipped on and off when needed. 

Designed as a reliable dive tool watch, the Seiko Padi SRPA21 boasts an excellent depth rating of 200 metres. This fulfills the ISO 6425 standards for dive watches, so you can bring this watch with you on all sorts of water adventures, including swimming and diving. 

The Seiko Padi SRPA21 retails at $419 USD, which is a very budget-friendly price for such a sturdy and practical dive tool.

Seiko Padi SUN065 

Next, we have the Seiko PADI SUN065. This watch shows off a more casual and sporty look. As such, it can double as both a dive watch and as the perfect everyday watch companion for all your daily routines. 

This watch is presented in a chunky 47.5mm stainless steel case with a thickness of 14mm and a thick, ridged silicone strap in black. It provides quite a bit of heft on your wrist, so this is a great choice for those with thicker wrists or who just prefer to wear large watches. Unlike other Seiko dive timepieces, the Seiko Padi SUN065 has a rather unique case shape, with cut-out lugs that give the watch a more angular and streamlined appearance. These cut-out lugs also serve to protect the watch’s bezel from any impacts. 

As an authentic dive tool, a unidirectional rotating bezel is placed on top of the watch’s case. It bears a rich blue aluminium insert for an elapsed time scale. This bezel matches well with the watch’s dial, which also comes in the same shade of matte blue. 

The dial is decorated with thick applique hour indices in various geometric shapes, broad arrow hands, and a small date window between 4 and 5 o’clock. It is also accented with red highlights, so that the watch stays true to the PADI theme. This dial also contains an additional, skeletonised GMT hand. It comes in beige white and striking red, serving as a bold contrast to the predominantly blue watch face. 

Unlike the Seiko PADI SRPA21, the Seiko PADI SUN065 runs on a quartz-powered movement. Ticking inside this watch is the in-house Kinetic Calibre 5M85. Although this first-class movement is battery-powered, it also cleverly integrates a rotor, much like the ones you can find in automatic watches. Rather than producing energy for the mainspring, however, the Calibre 5M85’s rotor is used to produce a power supply for the movement’s battery. This rotor utilises kinetic energy to constantly charge the Calibre 5M85. 

The Calibre 5M85 also comes with a power reserve indicator and a solid six-month battery life when fully charged. Finally, the Seiko PADI SUN065 is an ISO-certified timepiece that is capable of handling all sorts of diving challenges with its 200-metre water resistance capacity. 

You can purchase the Seiko PADI SUN065 for around $477 USD.

Seiko Padi SRPA21 vs. SUN065: A Quick Comparison

In terms of both build and design, there are some subtle differences between the Seiko PADI SRPA21 and the SUN065. First of all, the Seiko PADI SUN065 is slightly larger. It utilises a bulky 47.5mm case, while the SRPA21 weighs in at just 45mm. As a result, the Seiko PADI SUN065 is also a little heavier on the wrist. 

These two watches are also equipped with slightly different bezels. The Seiko PADI SRPA21 has a classic Pepsi bezel, reminiscent of the stylish Rolex Pepsi watches. The Seiko PADI SUN065, on the other hand, has a handsome blue bezel, which evokes a thematically-appropriate marine theme. That said, the difference between these two bezels is entirely cosmetic. Both the bezels of the SRPA21 and the SUN065 are made using scratch-resistant aluminium and bear indicators for elapsed time scales. As such, they are functionally very similar. 

Finally, the most obvious difference between the two models is that the Seiko PADI SRPA21 has a more formal and professional look with its all-stainless steel build. As a result, it is a great option if you are looking for a sturdy office companion. The Seiko PADI SUN065, on the other hand, is fitted with a comfy and thick black silicone strap. This gives the Seiko PADI SUN065 a more laidback and casual aesthetic, so it is perfect for your daily routines. 

When it comes to the watches’ inner mechanisms, there are some significant differences too. The Seiko PADI SUN065 runs on a Kinetic quartz movement. With an extensive six-month battery life, it is a good choice for anyone who wants to experience the superb accuracy of quartz movements. The Seiko PADI SRPA21, on the other hand, is a sophisticated automatic dive watch with a 41-hour power supply. One thing that remains the same, however, is that both movements are self-winding. 

Finally, both the Seiko PADI SRPA21 and the Seiko PADI SUN065 boast the same 200-metre water resistance capacity. Both watches are also ISO certified, so you can bring either of them on your deepwater expeditions.

Frequently Asked Questions 

What does PADI mean to Seiko? 

PADI stands for the Professional Association of Diving Instructors, which is the largest diving network worldwide. Seiko began its collaboration with PADI in 2016, and they have since released a couple of dive watches featuring the PADI name, logo, and its official colours.

Is Seiko PADI a good watch?

Absolutely. The Seiko PADI is crafted out of premium materials, which ensures that it delivers superior durability and stability even deep underwater. It also possesses all the traits an authentic dive watch needs, including a luminous dial display, a powerful movement, and an impressive water resistance capacity.

Where is Seiko PADI made? 

Seiko PADI watches are manufactured entirely in Japan. 

Alternatives to the Seiko Padi 

1. Citizen Promaster Eco-Drive Ref. CC5006-06 

Part of the highly-coveted Citizen Promaster collection, the Citizen Promaster Eco-Drive Ref. CC5006-06L is an all-rounder diver packed with top-of-the-line features. Like the Seiko Padi SUN065, this model uses a massive 47mm case. However, this watch’s case is made out of titanium, which weighs significantly less than stainless steel. As such, it wears quite lightly on your wrist. It is also paired with a rugged blue polyurethane strap with a handsome wave pattern. 

The dial of this watch shows off a deep blue finish, much like the Seiko SUN065. It is ornamented with thick geometric hour indices, oversized sword hands, and a trapezoidal date aperture at 3 o’clock. On top of the watch case, you can find a black and white count-up bezel with broad indicators that are easily legible. 

This Citizen watch runs on a robust Eco-Drive Quartz Calibre F158 movement. It offers a 200-metre depth rating and an outstanding +/-5 second per month accuracy rate. In addition, it also utilises light energy to power this watch, eradicating the need for any watch batteries. In fact, this watch holds the title of being the first-ever light-powered watch in the industry ever. 

The Citizen Promaster Eco-Drive Ref. CC5006-06 sells at around $1,189 USD.

2. Tudor Heritage Black Bay Ref. 79830RB-0002 

A great alternative to the Seiko PADI SRPA21 is the Tudor Heritage Black Bay Ref. 79830RB-0002. Hailing from “Rolex’s little sister”, this Tudor watch shows off a very high-end, fashionable design at a very affordable price. It sports a 41mm stainless steel case, coupled with a handsome brown leather strap. 

Sitting on top of the watch’s case is a sleek, two-tone GMT bezel, in the familiar Pepsi colours. The vibrant red and rich blue of the bezel contrast beautifully with the watch’s jet-black dial. This dial also contains luminous applique hour indices in various geometric shapes, Tudor’s classic snowflake hands, and a compact date complication at 3 o’clock. 

This Tudor Heritage Black Bay is powered by an in-house Tudor Calibre MT5652. It possesses a superb 70-hour power supply and a depth rating of 200 metres. 

The Tudor Heritage Black Bay Ref. 79830RB-0002 is priced at $3,689 USD.

Final Thoughts 

The Seiko PADI is easily one of the best, top-grade dive watches in Seiko’s ever-growing catalogue. Even though there are only a few models in this range right now, Seiko still offers a good amount of diversity to patrons, be it in terms of the watches’ design or the movements they use. This can be seen clearly in the contrast between the Seiko PADI SRPA21 and the Seiko PADI SUN065. So if you are hunting for an authentic diver watch to use for your next abyssal exploration, make sure to check out the Seiko PADI timepieces. 

All images courtesy of Amazon unless otherwise stated.

Featured image courtesy of (@SEIKOIndonesia) on Twitter.

Searching for a rugged dive watch fitted with lots of superior features? Don’t miss our review about the Hamilton Khaki Navy BeLOWZERO.