The Samurai has never been a particularly subtle dive watch. Its sharp case surfaces, large markers and bold shape give it a look you’ll either connect with immediately or probably never will.
That’s what makes the Seiko Prospex HBB001K interesting. Seiko hasn’t softened the familiar Samurai formula for its 145th anniversary. Instead, it has dressed it in a much brighter silver, white and blue colour scheme.
Personally, I think that contrast is the main reason to consider it. This isn’t simply a standard model with some anniversary text hidden on the back. You can see what makes it different as soon as you look at the dial.
Quick Take
• Limited to 9,999 pieces worldwide
• Silver-white dial with blue bezel and seconds hand
• 41.7mm stainless steel case
• Seiko 4R35 automatic movement
• Approximately 41 hours of power reserve
• Hardlex crystal
• 200m diver’s water resistance
• Stainless steel bracelet with clasp extender
What Makes This Anniversary Edition Different?
The Seiko Prospex HBB001K is based on the much-loved Samurai, retaining its straight, blade-like case surfaces and strong dive-watch proportions.
The anniversary identity comes from the use of blue accents inspired by “Seiko Blue”, a colour connected with the brand since the 1960s. Blue appears on the two-tone bezel and seconds hand, while the dial is finished in silver-white.
For me, that colour combination works because it changes the character of the Samurai without disguising it. You still get the angular case and oversized diving markers, but the brighter dial makes it feel less like another conventional dark-coloured tool watch.
Dial and Design
The silver-white dial has a subtle sunburst finish that responds to changing light, while the blue seconds hand provides a clear point of contrast. The two-tone blue bezel frames the dial without overpowering it.
Large hands and indexes keep the display easy to read. LumiBrite, Seiko’s luminous material that glows in low light, is applied to the hands, hour markers and bezel. The date display adds a practical everyday function without making the dial overly complicated.
This is probably the strongest part of the watch. There are plenty of capable Seiko divers, but the Seiko Prospex HBB001K doesn’t look like it’s trying to blend into the wider collection. The anniversary colourway gives you a genuine visual difference rather than relying entirely on its limited-edition status.
Case and Wearability
The stainless steel case measures 41.7mm across, 12.3mm thick and 49.5mm from lug to lug. It weighs 170g on its stainless steel bracelet.
The diameter doesn’t sound especially intimidating for a modern dive watch. The more important measurement is the 49.5mm lug-to-lug length, because that tells you how much space the case will occupy across your wrist.
Add the 170g weight and there’s no point pretending this will disappear under a cuff. It’s a substantial watch. Personally, I don’t see that as a flaw because the Samurai design is built around strong wrist presence. Still, if you prefer compact or lightweight watches, these are the numbers I’d pay closest attention to before buying.
Hardlex Crystal
The Seiko Prospex HBB001K uses Hardlex, Seiko’s hardened mineral crystal.
Hardlex is probably the easiest specification to question here. Some buyers will reasonably want sapphire on a limited-edition watch. Would that stop me considering it? Not by itself. But it does mean the main appeal has to come from the design, anniversary connection and Samurai case rather than from having the most ambitious possible specification sheet.
Seiko 4R35 Automatic Movement
Inside is Seiko’s 4R35 automatic movement.
• Automatic winding: The movement winds through the motion of your wrist.
• Manual winding: You can also wind the movement using the crown.
• Hacking seconds: The seconds hand stops when you set the time, helping you synchronise it more accurately.
• Power reserve: Approximately 41 hours when fully wound.
• Jewels: 23.
• Date display: A date window is included for daily convenience.
The 41-hour reserve isn’t extraordinary, but it’s perfectly understandable and easy to work with. Manual winding and hacking seconds also make the watch simpler to restart and set after it has stopped.
Bracelet and Clasp
The solid stainless steel bracelet has chamfered centre links that complement the straight lines of the case. Its three-fold clasp includes a secure lock, push-button release and extender.
The extender makes sense on a watch with genuine dive specifications, while the full steel construction reinforces its substantial feel. Again, this won’t be the right setup for someone chasing an especially light everyday watch.
Who Does This Watch Suit?
The Seiko Prospex HBB001K makes the most sense for someone who already likes the Samurai shape but wants a version that looks noticeably different from the standard collection.
It should also appeal to collectors who prefer limited editions with clear design changes. The silver-white dial and blue accents give you something more meaningful than a different case-back inscription.
Who should think twice? Anyone who wants a smaller, lighter watch or considers sapphire crystal essential. Those aren’t minor details, and there’s no reason to pretend otherwise.
How Does It Compare With a Standard Samurai?
The underlying Samurai personality remains intact. You still get the angular case, large luminous markers, automatic movement, unidirectional bezel, screw-down crown and 200m diver’s water resistance.
The difference is visual. The brighter dial and blue details give the anniversary model a cleaner, less conventional appearance. It isn’t a complete reinvention, but I don’t think it needs to be. It’s a recognisable Samurai with enough personality to justify its place beside the standard versions.
Final Verdict
For me, the colour scheme is what makes the Seiko Prospex HBB001K work. The silver-white dial brightens the Samurai design, while the blue bezel and seconds hand give it enough contrast to remain sporty.
It won’t suit everyone. The weight is substantial, the lug-to-lug measurement deserves attention, and Hardlex may disappoint specification-focused buyers.
But if you already like the Samurai and want one that won’t look like every other dark-dial diver, this anniversary edition makes a convincing case. The limited production is a bonus. The design is the real reason to buy it.
Seiko Prospex Diver's 145th Anniversary HBB001K Limited Edition
$950.00
The Seiko Prospex Diver's 145th Anniversary HBB001K Limited Edition celebrates Seiko’s 145th anniversary with a refined design inspired by the iconic “Seiko Blue” — a signature colour that has represented the brand since the 1960s. The fresh silver-white dial is… read more
Key Specifications
| Specification | Details |
| Model | HBB001K |
| Movement | Seiko 4R35 automatic |
| Power reserve | Approximately 41 hours |
| Case | Stainless steel |
| Diameter | 41.7mm |
| Thickness | 12.3mm |
| Lug-to-lug | 49.5mm |
| Weight | 170g |
| Crystal | Hardlex |
| Water resistance | 200m diver’s |
| Bracelet | Stainless steel |
| Limited production | 9,999 pieces worldwide |
FAQs
Is the Seiko HBB001K automatic?
Yes. It uses the automatic Seiko 4R35 movement, which can also be wound manually through the crown.
How large is the Seiko HBB001K?
The case is 41.7mm wide, 12.3mm thick and 49.5mm from lug to lug. It weighs 170g with the stainless steel bracelet.
Is it suitable for diving?
It has 200m diver’s water resistance, a unidirectional rotating bezel, screw-down crown, screw case back and bracelet extender.
Does it have a sapphire crystal?
No. The watch uses Hardlex, Seiko’s hardened mineral crystal.
How long is the power reserve?
The 4R35 movement provides approximately 41 hours of power reserve when fully wound.
How limited is the HBB001K?
The Seiko Prospex HBB001K is limited to 9,999 pieces worldwide and has “LIMITED EDITION” marked on the case back.
