Seiko's Best Diver Just Got Better!

I have owned the Seiko Marinemaster SBDX001 for over ten years, and this model impresses me as much as it did back in 2015.

Nonetheless, the original Marinemaster had some shortcomings. For instance, the Hardlex crystal, steel bezel, and the feeling of unreliability in the clasp and diving extension. After the release of the SBDX001, Seiko introduced many new models, but not all of them addressed these issues. With the arrival of the Marinemaster HBF001, the brand has finally made some fundamental changes. Could this be the best Marinemaster to date?

Seiko Prospex Marinemaster HBF001: Key Features

Let's start with the main point: the new Marinemaster HBF001 does not use a monobloc case like some earlier models, but it has received a number of interesting updates. Most importantly, it transitions from the Seiko 8L35 caliber to the 8L45. The 8L45 movement is based on the Grand Seiko 9S65, while the 8L35 is derived from the earlier 9S55. The model with the 8L45 caliber provides a power reserve of up to 72 hours, as indicated on the dial, and also boasts improved accuracy.

Major Model Updates

Another significant improvement is the new bracelet and clasp. It was precisely the clasp with the diving extension that prevented my reliable Marinemaster SBDX001 from becoming almost perfect.

Advantages of the New Bracelet

In the new version, the bracelet has become much sturdier and features a micro-adjustment system that works flawlessly. The extension can be adjusted up to 16 mm in 2 mm increments, significantly enhancing comfort when worn with a wetsuit.

Ceramic Bezel Instead of Steel

Previously, Seiko updated earlier models by replacing the Hardlex crystal with sapphire. Now, a ceramic bezel insert replaces the steel one, improving the watch's durability and appearance.

Technical Specifications Seiko Prospex Marinemaster HBF001