Seiko's new Prospex collab is beautiful, but why is a $750 limited-edition watch running a budget movement?

Seiko and PADI have a genuinely good story to tell with their new launch. Ten years of partnership, five years of ocean conservation support through the PADI Aware Foundation, and now a handsome limited-edition diver's watch to celebrate six decades of the world's largest diving organization. The HBB002 earns its looks, no doubt. It has a deep blue ceramic bezel, a globe-motif dial from PADI's 60th anniversary logo, red accents at six o'clock, and Seiko's classic diver silhouette with the crown at four. It ships with both a stainless-steel bracelet and a silicone strap printed with PADI's full name. Presentation-wise, Seiko has done the collab justice.

Then you flip it over.

Inside the HBB002 is the Caliber 4R36 — the same movement Seiko has been fitting into its entry-level Seiko 5 Sports watches since 2011. It runs at 21,600 vph with a 41-hour power reserve and a rated accuracy of ±45 seconds per day. That tolerance is, to put it diplomatically, generous. Real-world results are often better than the spec suggests, and the movement is reliable and easy to service — but that's not really the point. The 4R36 is the movement Seiko puts in a near-$300 Seiko 5 Sports watch, like the SRPD65 - curr. $316 on Amazon. The HBB002 costs $750.

For context, Seiko's own Prospex Sumo — a non-limited diver starting in the $600-$650 range (current prices, not retail) — already gets the 6R35, which brings a 70-hour power reserve and much better finishing. The 6R35 is what Seiko itself describes as a powerhouse movement, with enough torque to drive high-intensity diver's models while still slim enough for dress watch applications. Go a little further up the range and the it gets harder to justify: the Marinemaster (MM200), Seiko's flagship professional diver, starts at around $900 and comes with some serious specs.

The HBB002 comes in at $750 — above Sumo, below Marinemaster — but gets the movement from a watch that costs nearly a third of the price. Seiko has also fitted the 6R35 into several of its own limited edition Prospex releases at comparable or even lower price points, which making the choice of the 4R36 here feel like a cost-saving measure. Sure, Seiko is slowly bumping pricing up across some of it catalog, but at $750 here, your choices are either a sick-looking limited-edition watch, or a better watch.  

None of this makes the HBB002 a bad watch. The ceramic bezel, sapphire crystal, 200-meter water resistance, and Lumibrite application are all exactly where they should be (for the price, at least). The story behind it is great. But watch aficionados — who will make up a big chunk of those 8,000 buyers — will notice the movement, and they'll definitely talk about it.

The HBB002 arrives at select US retailers in July 2026, priced at $750.