Seiko Prospex 1965 Heritage Diver’s Special Edition SPB455J1

Introduction

Introduced in 2020, the Seiko Prospex SPB143J1 debuted a new take on the original 1965 diver’s case. With sleek, uncluttered lines and a symmetrical case with no crown protectors, the SPB collection debuted a design trend across a range crowded by Sumo and Turtle, drawing inspiration from the 62 MAS yet with a more contemporary look.

The straight, no-frills cues and a clever price point commercially boosted the SPB series. A simple, easy-to-read dial and an acceptable spec sheet made it a hero product. It has evolved in shape and performance to celebrate Seiko’s 100th Anniversary anniversary.

The new Seiko Prospex 1965 Heritage Diver’s Special Edition SPB455J1

Simplicity is timeless. Some watches raise the chart without effort, and the SPB series is among them. The flat case design, square and bold from atop, and with straight lugs, showcases a curved side design to extend the lug-to-lug distance to guarantee wearing comfort as much as the correct proportions between the parts.

The Special Edition model pictured here is part of the renewed collection, featuring three references. It continues to offer a compelling proposition to those exploring the Prospex Diving series, delivering impressive performance within a budget of less than 2,000 Euros.

When considering the SPB455J1, it is impossible to ignore its predecessor, the SPB147J1.

Case and bracelet.

You may not notice any significant changes compared to the 2020 edition. However, upon closer inspection (and a review of the official specs sheet), you will discover that the changes are subtle yet impactful. The case has been slightly downsized to 40.0 mm, the thickness has slimmed to 13.0 mm, and the lug-to-lug distance has decreased to 46.4 mm.

Overall, the case underwent a detailed redesign to improve its aesthetic appeal and elevate the daily experience with this Prospex.

The new SPB455J1 is inspired by the previous version (SPB147J1). However, it adopts a colour combination similar to the outgoing one, with an anthracite grey dial and a black bezel featuring a fine-grain finish.

Such details make the SPB455J1 more compliant and include an excellent integration of the dial and bezel and vice versa.

The bezel’s metallic inlay now houses a continuous minute track, with dots appearing towards the Arabic numerals, as opposed to SPB147J1’s layout.

Look above and immediately discover what sets the two Seiko models apart. Finally, the date window on the new Marinemaster has moved to 16:30.

Yes, it has a date window, but no, you will not notice it anymore. Moving the date window away from the ordinary three o’clock position adds to the dial’s symmetry since the model houses a complete LumiBrite™-filled index.

This feature improves the watch’s visibility in low light conditions, dramatically boosting the luminescence.

You might hardly notice the reworked bracelet’s design; the links are shorter than before, and the folding clasp is smaller. Under the hood, there is a pimped-up timepiece: the Seiko SPB455J1 100^th Anniversary is a 300m water-resistant watch.

Seiko’s caliber 6R55

The Seiko Prospex 1965 Heritage Diver’s Special Edition SPB455J1 is powered by the 6R55 calibre, an evolution of the 6R35 calibre. As written on the dial, it boasts a power reserve of up to 72 hours.

The new movement debuted about a year ago (February 2023) to celebrate 110 years since the launch of the first-ever Japanese wristwatch. The 39 mm large King Seiko debuted the 6R55 movement.

Its accuracy is in line with the 6R35’s. It is in the +25 to -15 seconds per day range (when tested between 5 and 35°C). It has all the features of Seiko mechanical movements, like the Diashock anti-shock system, the Spron 510 hairspring, the Magic Lever bidirectional winding system and a resistance to magnetic fields up to 4,800A/m.

As written on the dial, it boasts a power reserve of up to 72 hours. It means that the watch can continue operating for up to 72 hours without a wound, providing convenience for the wearer, especially during periods of inactivity.

Final thoughts

It is mostly about evolving with the newer Seiko SPB455J1. You will not change what works; you will improve it according to the Kaizen philosophy.

Seiko took its Anniversary to evolve the SPB and added far more value—it is the first-ever Prospex to house the 6R55 calibre and is a 300-meter watch—without consistently upgrading the list price, which stops at the 1,600 Euros threshold as long as the Limited-Edition model is concerned.

Aesthetically pleasing, refined, and bolder than ever, the Seiko Prospex SPB455J1 stands out thanks to the new date window’s placement and the redesigned bezel.

Its performance, with a power reserve of up to 72 hours and a water resistance of 300 m, is equally impressive. It is no wonder that this watch is a top choice for those seeking a high-quality, stylish timepiece.

The special edition also has a replacement fabric strap manufactured via plastic bottle recycling. While we like such a choice, going underwater requires a rubber option with a pin buckle as the summer holidays are approaching. Here is our favourite choice for a replacement steel bracelet. For additional information, please visit the official Seiko website.

(Photo credit: Horbiter®)

Giovanni Di Biase @Horbiter®