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Dive Watch Distilled: Meet The Seiko Prospex SRPA21

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Looking for a bit of functional bling? The Prospex Seiko SRPA21 dive watch brings legendary quality and value in a modernized package.

Long ago, scuba divers used dive watches primarily as a niche tool to measure intervals underwater. With the advent of dive computers, they became less necessity and more luxury. But even so, the dive watch market is booming thanks to its remarkable day-to-day wearable functionality.

And yes, you can still use them to measure dive intervals too.

We spoke with Eric Hofmann, senior vice president of business development at Seiko, to learn about the new SPRA21, a watch developed in conjunction with the recreational diving juggernaut PADI.

The Seiko SRPA21 Dive Watch

What sets the Seiko SRPA21 apart from other watches on the market?

Design and history dating back to the 1970s. Its unique aesthetics include a smooth and rounded contoured case as well as a blue dial with Seiko’s automatic in-house movement. Overall, it is an attractive and functional sports watch. The PADI “turtle,” as many fans have nicknamed it, is a true diver’s watch that meets ISO (International Standards Organization) standards. The quality of the LumiBrite hands and markers matches or even exceeds many luxury brands for a fraction of the cost: $550.

What are some of the primary uses of this watch?

Besides being a diver’s watch, the SRPA21 could really be used for most occasions because the case fits well and conforms to the shape of the wrist. It’s attractive aesthetically and wears smaller than the case diameter suggests. The durable design and technology make it perfect for most activities, from water sports like scuba diving (for non-saturation diving), snorkeling, and swimming. It is also practical for general sports and outdoor activities like hiking because it is more shock resistant due to the ISO standards.

Would you expect divers to use this as a secondary watch to a dive computer?

Yes, a diver may choose to use this as a backup in case anything happens to their electric-powered dive computer. The SRPA21 has automatic movement and does not require a battery or electrical power. The built-in unidirectional rotating bezel shows elapsed time to help divers time track their adventure.

However, this can also be used for recreational swimming or snorkeling when it would not be practical to bring a dive computer or cell phone.

Can you explain the ‘Divers Automatic’ movement? What does this mean?

Automatic movement does not require a battery, instead, the watch self-winds with the body’s natural movement. To be a “Divers Automatic” the watch must adhere to ISO-specific standards for water resistance, shock resistance, anti-magnetic properties, and maintain its accuracy under such conditions.

How does this watch improve upon some of the classic Seiko watches from years past, such as the SKX007?

The SRPA21 has an updated caliber – 4R36 versus the 7S26 of the SKX007. In addition to being automatic, users can also wind this caliber manually.

The hacking seconds feature also improves on other classic Seiko watches. It enables the second hand to stop when the crown is pulled out to allow for more accurate synchronization to the time standard. The SRPA21 also has a more iconic design from Seiko’s heritage.

Why did Seiko partner with PADI on this watch?

SRPA21 was the first, and most celebrated, of Seiko’s exclusive PADI (Professional Association of Diving Instructors) “Special Edition” releases. It is a true dive watch, meeting ISO 6425 standards.

PADI is the world’s largest and most trusted association of its kind. It has issued more diver certifications than anyone else. Having two of the most trusted organizations in its field working together is truly a unique quality set that goes unmatched.

I read that the vintage Seiko 63XX series, a.k.a the Seiko turtle, inspired this watch. What does it draw from this 1970s model, and how does it improve upon it?

While keeping the rounded signature case and size proportion, which is true to the original, Seiko improved the caliber to a 4R36. The original caliber was self-winding only, without the hackable second feature as listed above. Seiko also improved water resistance from 150 meters to 200 meters.

Who should choose this watch?

Collectors, divers, or someone that demands style, and also likes the look and feel of a watch that supports an active lifestyle. The luminous hands are useful for both divers and everyday routines in low-light situations.

In addition to using it for diving, this watch provides an added peace of mind that it will withstand water during day-to-day activities.


This article is sponsored by Seiko. Learn more about the SRPA21 here

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