The Seiko HBC005 and HBB001: Two Anniversary Divers In ‘Seiko Blue’

Seiko is in the midst of its 145th anniversary, and with that comes a slew of new releases across the collection. Here I am going to be focusing on two dive watches in the Prospex line, one that takes the form of the 1965 format and the other a take on the Samurai. These are the HBC005 and the HBB001, respectively.

Both watches are utilizing base formats of updates to each of these design templates over the last 2-3 years for Seiko, the Samurai being the most substantive design change that was recently made popular with the “Red Samurai.”

The 1965 format is iterating from a historical standpoint off of the original 62MAS, but in reality, it is a slight change from the design first introduced with the Seiko SPB143. Minor changes have been made to the date window and overall thinness and wearability, but mostly these have been refinements to a much-loved format.

Because these are anniversary releases, these watches are not going to be in the permanent collection. That being said, the numbers are limited in such a way that it won't be impossible to secure whichever one you fancy most.

Both watches utilize a color called “Seiko Blue,” which was first established by the brand in the 1960s, but each watch deploys that blue in a different way, so let’s get into each watch.

The HBC005

So we will start out with the 1965-inspired HBC005, which combines a sunburst silver-tone dial with a rich blue bezel. The blue theme is punctuated by the running seconds hand with its prominently lumed rectangular end.

This watch is such a known and loved format at this point that there isn’t a whole lot that needs to be said here, but I’ll still say a few things despite that fact.

The case diameter on this one is 40mm with a thickness of 13mm and a lug-to-lug of 46.4mm, all extremely wearable specs. The crystal is a curved sapphire. The lug width is 20mm, which is fantastic for strap swapping, and the watch is affixed to a three-link bracelet style that not only looks good but feels exceptional for the price.

Inside the watch beats the Seiko 6R55 movement with 72 hours of power reserve and 24 jewels, and offers hacking and handwinding. The lume on the dial is Seiko’s signature LumiBrite.

The dial lists the three days of power reserve front and center, and the only design point you might not be used to here is the date placement at 4:30, but at least it's a head-on and not slanted view of the date. No, this isn't new to this watch in particular, but it is a relatively recent design change overall.

The HBB001

And next comes the Samurai, which is by far the more playful of the two watches, but it’s no less a serious dive tool. Here, you get all of the aggressive styling that you are accustomed to on a Samurai, down to the knurling on that pronounced crown.

The new design elements remain, such as the re-formatted and redesigned numerals on the bezel, the overall “traditionalization” of the wear experience. But where most Samuai models deploy a monochromatic approach, this one plays with color, tone, and contrast.

That Seiko blue is prevalent on part of the bezel, but for the first 15 minutes worth of dive-time, which takes on a textured grey tone. The blue persists on the dial via the central seconds hand, and the dial itself is the same sunburst silver as the HBC005.

In terms of sizing, here we are looking at a 41.7mm case diameter at 12.33mm thick with a lug-to-lug of 49.55 – absolutely a more contemporary size. The crystal used here is Seiko’s proprietary Hardlex.

Inside beats the workhorse 4R35 with 41 hours of power reserve, 23 jewels plus hacking and handwinding. You will also find the aforementioned 4:30 date display.

Pricing for the HBB001 is $595, while the HBC005 will be priced at $1,400. Both are expected to land this June, 2026.

For more information, visit the brand's website here.