Big news from Seiko today, as the brand announces a follow up to their wildly popular SPB143 diver (and its many siblings). The new SPB453, SPB451, and SPB455 use the same 62MAS derived format but offer small changes in specs that make the new versions of the watch correspondingly more appealing. It’s not a revolutionary update in design or anything, but a series of small changes that should result in a better experience for just about everyone, and reinforces the idea that this watch, the “1966 Diver’s Re-Interpretation,” is the core diver in Seiko’s lineup and will be forever tinkered with in an almost Rolex kind of way.

Let’s start with the big changes, which are actually quite small in a literally sense. The new references have been tidied up a bit in their dimensions and are slightly smaller in every dimension watch enthusiasts care about than their predecessors. The diameter is down half a millimeter to a clean 40mm, and the case height has been reduced to 13mm, which is a barely perceptible 0.2mm thinner than the SPB143. The lug to lug measurement is 46.4mm, which is a more noticeable 1.4mm shorter. 

The new case size is welcome, in my opinion. It’s not that the SPB143 wore too large or was too aggressively chunky, but for a diver like this a little extra refinement is a good thing. A skin diver style dive watch isn’t meant to be a behemoth on the wrist, but rather the ideal combination of wearability and performance for regular folks. Getting this watch marginally smaller in each dimension is a reflection of watch’s original intent. It should be noted as well that the bracelet has undergone a change as well, with shorter links and a smaller clasp that promise a more comfortable fit. 

The other changes we’re seeing with this new crop of watches are more technical. The most impressive is that water resistance has been improved by a full 100 meters: this is now a 300 meter water resistant diver. To be able to increase water resistance while making the case smaller is a pretty major technical achievement on Seiko’s part, particularly in a watch that’s still squarely aimed at a mass market (the retail price for these new watches on a bracelet comes in at $1,300). 

We also see a new movement (the 6R55) and a date window moving from 3:00 to 4:30. The 6R55 has popped up in a few other recent Seiko and King Seiko releases. It’s a slightly thinner caliber than the 6R35 and offers a few extra hours of power reserve (72 versus 70). The new date window placement seems to be a result of a desire to keep the 3:00 marker at full size. To Seiko’s credit, the new date window is color matched and circular, making it about as clean an execution of a date in this position that you can expect. 

That brings us to the dial variants for this first batch of new watches. If history is a guide, we’ll surely see more variety as time marches on, but for now we have option in black (SPB453), blue (SPB451), and gray (SPB455). The latter reference is a special edition, and features gold accents on the dial furniture and bezel. It also comes with a fabric strap made from recycled plastics. 

We’re looking forward to seeing these watches in the metal soon, and comparing them in even more detail to the previous generation of SPBs. This update is expected to hit Seiko retailers in June. Seiko