The Updated 62Mas-Inspired Seiko Prospex 1965 Divers 300m Collection

Prospex 1965 Divers is a name that means a lot at Seiko. It refers to what’s probably the most classic dive watch collection of the brand, which, as you might have guessed, finds its origins in a 1965-designed watch. But we’re not talking about any watch, or any Seiko dive watch for that matter, but the brand’s inaugural foray underwater, its first dive watch, Japan’s first professional dive watch: the all-time important 62Mas. Still as relevant as it used to be, it has served for several years as an inspiration for modern aquatic tools and continues to do so as Seiko just updated the Prospex 1965 Divers collection with the SPB451, SPB453 and SPB455… And these are at the heart of our latest video review. 

It’s not the first time we’ve talked about the Prospex 1965 series. And for obvious reasons. This collection can be traced back to one watch: Seiko’s very first diver, the 62MAS. Introduced in 1965 as reference 6217-8000 and nicknamed 62MAS, indicating the movement as part of the 62 calibre family and with MAS referring to “autoMAtic Selfdater” or “SeikoMAtic Selfdater”, this watch set the tone for most subsequent dive watches of the brand—more on this topic in these articles here and here.

What’s more relevant today is that Seiko has, since 2017 and the faithful re-edition of the original 62Mas, used this relatively simple style as a base for multiple collections, ranging from accessible to high-end and from classic to more original. What we’ll be focusing on today are mid-range watches from Seiko, with reference numbers starting with SPB. For about four years, the intermediate Seiko Prospex 1965 Divers collection was represented by three models, the SPB143, SPB147 and SPB149. This year, in a typical “evolution, not revolution” approach, the Japanese watchmaker released an update on this much-appreciated range, bringing incremental upgrades to the design, the proportions, the specs and the movement.

So here’s the 2024 Seiko Prospex 1965 Divers 300m collection—the water resistance in the name should already give a first indication of the evolution—comprising two classic references, the blue SPB451 and black SPB453, and one special edition in celebration of the 100th anniversary of the Seiko brand, the charcoal SPB455.

What has changed?

While you can find out about all the evolutions in the video above, here’s a summary of what has been updated on the Prospex 1965 Divers collection this year, compared to the previous editions:

• Slightly reduced case diameter – 40mm vs. 40.5mm
• Slightly reduced thickness – 13mm vs. 13.2mm
• Shorter case – 46.4mm vs. 47.6mm
• Screw-down crown now slightly recessed for better ergonomics
• Water-resistance now at 300m (vs. 200m in the past)
• More pronounced polished bevels on the side
• Steel case retains the super-hard coating
• Unidirectional bezel still with a metallic insert, but now matte instead of circular brushed

As for the dials, there are no major updates except for the date window:

• Overall, identical design for the embossed markers and hands
• New “automatic 3 days” and “Diver’s 300m” mentions at 6 o’clock
• Dial and bezel are now colour-matched (black on black, blue on blue)
• The date window has been relocated to 04:30 due to new ISO 6425 requirements and to bring a symmetrical design

Seiko introduces a new movement to this collection:

• Calibre 6R55 replaces calibre 6R35
• Extended power reserve (72h vs 70h)
• Accuracy within a range -15/+25 seconds per day minimum (often tested to much smaller tolerances)

New design for the bracelet and clasp:

• New 3-link bracelet with shorter links for more flexibility
• New folding clasp, shorter than before, for better ergonomics
• Still equipped with a safety closure, pushers and a diver’s extension
• The SPB455 special edition comes with an additional braided textile NATO-style strap

For even more details about these new Seiko Prospex 1965 Divers 300m SPB451, SPB453 and SPB455, as well as our final opinion regarding this update, make sure to watch the video at the top of this article. For more details about the watches, please consult www.seikowatches.com.