Seiko Prospex SPB451, SPB453, SPB455

Seiko’s New Prospex Models are an Updated Ode to the 1965 Heritage Diver

The three recently unveiled Prospex models from the Japanese watchmaker lean into the heritage of an illustrious dive watch while blending in some welcome modern innovations.

By Mike Espindle
Executive Editor

When Seiko introduced its first dive watch (and, coincidentally, the first Japanese-produced dive watch) in 1965, it was something of an instant hit. That was because its mix of technical ability and reliable functionality was perfectly situated to deliver serious appeal to the growing community of recreational SCUBA divers without sacrificing the needs of professional divers.

While Seiko has constantly pushed boundaries and innovated in the dive watch arena over the ensuing years, the new black-dial SPB453, blue-dial SPB451, and Special Edition charcoal and gold execution commemorating the 100th Anniversary of Seiko watches, the SPB455, marvelously take that legend even deeper for dive watch aficionados.

Shared Innovations

The first innovation I want to discuss is actually a nod to heritage: a smaller case size. More specifically, while many modern Prospex watches are closer to 42mm in size, all three new Prospex models are crafted in a smaller, vintage-informed 40mm steel format.

This subtle shrink, at least in the opinion of this writer, is a plus because it further reduces negative space on the dial and allows the simple bar-and-hashmark indices to read as even more technical.

The original inspirational Seiko dive watch boasted water resistance of 150 meters (not too shabby in its days), and most contemporary core Prospex models clock in at a more modern 200-meter depth rating. However, these new dive watches carry a new 300-meter rating for water resistance (which is proclaimed front-and-center at 6 o’clock on the dials), further amping the pro-diver chops of the Prospex line.

Without going into great detail, that added pressure resistance was achieved with some involved mathematics by redesigning the inner case components to be more angular. Plus, their case lugs have been shortened, as well, for added comfort. Yet, despite these changes, the height for these new divers is still a slim 13mm, making it a cozy, comfortable wear both at depth and above the waves.

Change of Date

Most “classic” dive watch designs utilize a traditional square-window date aperture at 3 o’clock with a black date on a white background, for the most part. But when you think about it, the last thing you should care about while actually diving is the current date (unless you are sleeping in some kind of pressurized underwater chamber or something).

So, what’s the big deal with having a date window at 6 o’clock? Well, when diving, if you set your “time to go back up” with your dive bezel anywhere near the right-center of the case, it’s been my experience that a large square date aperture can actually cause some visual confusion.

Don’t get me wrong, I understand that it’s a nice feature to have above the waves, but dive watches are supposed to be functional underwater tools that help keep the diver safe first and aesthetically pleasing land accessories second.

Thankfully, on the SPB453, SPB451, and SPB455, Seiko’s designers have reduced the date indicator to a small circular aperture with white numerals atop a black background. Also, they moved its location from 6 o’clock to between 4 and 5 o’clock.

This is a terrific modification we should have seen years ago! Plus, it takes nothing away from the authentic appeal of the dial design nor from date legibility; it just kind of tucks it back for real-world use underwater.

The Color of Water

Sharing the modern 6R55 automatic movement with a 72-hour power reserve and the expected abundant LumiBrite coating on the hands, indices, and bezel, the differences between this trio begin to show when you examine the colorways.

The black-dialed SPB453 clearly exhibits the most direct lineage to the original 1965 diver. Meanwhile, a shimmering, blue-dialed version, like the SPB451, is a “new classic” for dive watches, given its obvious chromatic ties to H2O.

Finally, the SPB455 Special Edition goes the extra design mile, as it’s also a commemoration of the brand’s 100th anniversary. Its noteworthy dial is predominately charcoal grey but contains a fair few bronze-brown details enhanced by gold-tone hands, hash marks, bezel gauging, and index framing.

Something else the new Special Edition model has that the other two don’t: along with a traditional three-link steel bracelet, it also comes with an additional,

Of course, dive watch straps made from recycled materials are nothing new. However, Seiko’s execution is particularly flexible, air-permeable, and handsome as it was crafted using a distinctive traditional Japanese braiding technique called Seichu; it’s a nice little detail to add to your list of bragging rights on this watch.

Pricing & Availability

These new Prospex timepieces will be available this June at select Seiko retailers and via the brand’s website. Prices start at $1,300 for the black SPB453 and the blue SPB451. Meanwhile, the Special Edition SPB455 will list for $1,400.

(Images © Seiko)

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