Seiko’s been building dive watches since 1965, when their first diver, the 62MAS, was worn on the wrist of Japanese researchers during their South Pole trek. Three years later, the brand dropped Japan’s first 300m water-resistant diver, the 6159-7001, a watch so important that Seiko is still riffing on it nearly 60 years later.
The Marinemaster was the offspring of that legacy, a pro-level dive watch debuting in 2000 but as repositioned just three years ago as more of an homage to the ’60s models. Now, Seiko refreshes the design once again with two new Prospex Marinemasters that frankly look amazing.
Same Bones, Better Everything
Both watches share a 42.6mm stainless steel case at 14.1mm thick (slightly up from the prior generation due to a new movement) with a 49mm lug-to-lug. You get the same iconic flowing silhouette and screw-down crown at 4 o’clock that traces directly to the 1968 original. What’s new is the ceramic bezel insert that replaces the old steel version, a super-hard coating on both the case and bracelet, and a completely redesigned folding clasp with a toolless micro-adjust system. For the latter, it can extend up to 16mm in 2mm increments, which you can even retract while the watch is on your wrist.
The bigger headline under the caseback is the 8L45 caliber, Seiko’s best non-Grand Seiko automatic. Running at 28,800vph with 35 jewels, it delivers a 72-hour power reserve (up from 50 on the outgoing 8L35) and tightens accuracy to -5/+10 seconds per day. The mainspring and hairspring are both Spron alloy, Seiko’s proprietary material, and the crown is seated in a replaceable tube rather than threaded directly into the case, a long-overdue fix. This is the same movement found in last year’s 600m Marinemaster Professional Titanium SLA081, so it has some serious pedigree already.
The Standard-Bearer: HBF001
The black-dial HBF001 is the one that’ll move units. It keeps the refined texture and applied Lumibrite-filled indices of its predecessor but relocates the date window from 4:30 to 3 o’clock for better visual balance. The dial’s fine-grain surface is designed to minimize light scatter underwater, which is a functional detail that supercedes form, but looks good while doing it. It also now reads “Automatic 3 Days” rather than just “Automatic,” referring to the new movement. Either way, this watch is a clear step up from the SLA079, and at $3,600, it still undercuts the least-expensive Tudor Black Bay by a meaningful margin.
The Statement Piece: HBF002
The JAMSTEC limited edition is something else entirely. Seiko’s partnership with Japan’s marine research agency goes back to 1983, when two Seiko professional divers were tested aboard the SHINKAI 2000 submersible. That relationship is the foundation for this 1,000-piece limited run, inspired by Japan’s first icebreaking research vessel, the Mirai II, scheduled for completion this year.
The textured blue dial replicates the fractured trail of an icebreaker cutting through sea ice, with a vertical gradient that deepens at the center, all finished under a thick polished lacquer. Complete with a gold seconds hand, this is a bold piece, and maybe too bold for some, but it’s ambitious and one of the most stunning Seiko divers we’ve ever seen.
Spec Sheet
Model: Seiko Prospex Marinemaster 1968 Heritage Diver’s Watch
References: HBF001 (black dial) / HBF002 (JAMSTEC Limited Edition)
Case Material: Stainless steel with super-hard coating
Case Size: 42.6mm
Case Thickness: 14.1mm
Lug-to-Lug: 49mm
Crystal: Dual-curved sapphire with anti-reflective coating
Movement: Seiko Caliber 8L45 automatic
Water Resistance: 300m
Lume: Lumibrite on hands and indices
Bezel: Ceramic insert (black on HBF001, blue on HBF002)
Bracelet: Stainless steel five-row with toolless micro-adjust clasp
Limited Edition: HBF002 limited to 1,000 pieces
Price: $3,600 (HBF001); $3,900 (HBF002)
Pricing & Availability
Both Marinemaster models hit Seiko boutiques and select retailers worldwide in July. The HBF001 is a permanent collection piece priced at $3,600, while the JAMSTEC HBF002 is limited to 1,000 pieces at $3,900.
Recap
Seiko Prospex Marinemaster 1968 Heritage Diver HBF001 & JAMSTEC Limited HBF002
Seiko just refreshed its flagship Marinemaster dive watch with two new models rooted in the iconic 1968 6159-7001, bringing a much-needed movement upgrade to the 8L45, a new toolless micro-adjust bracelet clasp, and ceramic bezel inserts to the table. The HBF001 is the everyday keeper, while the 1,000-piece JAMSTEC HBF002 steals the show with a textured, glacier-inspired blue dial that’s unlike anything else in the lineup.
