Video: The Best Seiko Diver Just Got Better!

I’ve owned my Seiko Marinemaster SBDX001 for over ten years, and it impresses me as much today as it did back in 2015. However, the original Marinemaster had some “flaws.” Such as the Hardlex crystal, steel bezel insert, and flimsy-feeling clasp and diving extension. Seiko released many references after the SBDX001, but not all of them addressed its shortcomings. With the Marinemaster HBF001, the brand finally made several fundamental changes. Could this be the best Marinemaster yet?

Check out the video below for a full hands-on look.

Seiko Prospex Marinemaster HBF001

Let’s address the elephant in the room: this new Marinemaster HBF001 does not use a monobloc case like some of the early Marinemasters, but it does come with some rather interesting updates. Most important is the upgrade from Seiko caliber 8L35 to 8L45. The 8L45 movement is based on Grand Seiko’s 9S65, whereas the 8L35 is derived from the earlier 9S55. The Seiko 8L45 offers 72 hours of power reserve, as stated on the dial, and has improved accuracy.

Seiko Marinemaster SBDX001 and HBF001

Major updates

The other major improvement is the new bracelet and clasp. The clasp and its diving extension are what kept my trusty Marinemaster SBDX001 away from being near-perfect.

Seiko Marinemaster HBF001

This is all fixed with the new bracelet, which is much sturdier and has a micro-adjustment system that works perfectly. In total, you can extend to 16mm in 2mm increments.

The update also includes a ceramic bezel inlay

Seiko has already updated the previous iterations from Hardlex (mineral) crystal to sapphire, and now we can also find a ceramic bezel insert instead of a steel one.

All specifications can be found in the chart below. For more information, visit the official Seiko website.