Seiko’s been on a roll lately, debuting some superb models to commemorate the 60th anniversary of its first dive watch (62MAS). Just in the past few months, we’ve gotten the 600m Marinemaster in titanium and a limited-edition take on the 1968 Heritage Diver’s GMT, finally bumping the 200m of water resistance to 300m.
For its latest release, the Japanese watchmaker took this 60th anniversary model (SPB509) and found it a permanent home in its collection, keeping the 300m depth rating of course while adding a fresh new colorway.
A Brief History Lesson
Seiko’s dive watch lineage reaches all the way back to 1965, but it wasn’t until 1968 that they created their first 300m timepiece (simply called the Diver’s 300M). That milestone serves as the spiritual ancestor for this new Prospex GMT, with its distinctive case design sporting those signature angular shoulders and raised bezel profile.
Fast forward to 2023, and Seiko finally decided to merge their dive watch expertise with GMT functionality for the first time, launching the SPB381, SPB383, and SPB385 series. However, those models offered just 200m of water resistance and lacked the micro-adjustable clasp that serious dive watch enthusiasts crave.
Earlier this year, Seiko addressed these shortcomings with the SPB509, adding the aforementioned 300m depth rating as well as a coveted six-position micro-adjust clasp. The SPB519 we’re looking at today essentially makes those premium improvements available to the masses, just with a different aesthetic approach.
Clean Aesthetics With A Pop Of Color
Swapping the blue wave-stamped dial of its limited-edition predecessor for a sunray-brushed white one (sans waves), the SPB519 takes a cleaner, more restrained approach. The silvery dial provides a stark, legible canvas that practically screams “professional tool watch.” But for balance, Seiko wisely introduces vibrant red accents on the GMT hand, seconds hand, and “GMT” text. Combined with a blue ceramic bezel, the overall effect blends the utilitarian approach with visual appeal.
The oversized markers and chunky hands remain, all generously filled with Lumibrite for exceptional nighttime legibility. Meanwhile, the brand’s signature 4:30 date window returns to round out the dial.
Technical Improvements Matter
Aside from looks, the real story here is about how Seiko is finally giving their standard-production GMT divers the same technical upgrades previously reserved for limited editions. The move from 200m to 300m water resistance is welcome, even if most wearers will never dive deeper than their hotel pool. More importantly, that six-position micro-adjustable clasp is truly a game-changer for daily comfort. Each adjustment provides roughly 2.5mm of wiggle room, for a total adjustment range of 15mm. This means the watch can easily accommodate wrist swelling during hot days or diving conditions, and then be quickly tightened back up when needed.
Housed inside the 42mm stainless steel case is Seiko’s in-house 6R54 caliber, which offers a respectable 72-hour power reserve but utilizes an “office GMT” setup rather than a true traveler’s GMT.
Spec Sheet
Case Size: 42mm
Lug-to-Lug: 48.6mm
Case Thickness: 13.3mm
Case Material: Stainless steel
Water Resistance: 300m
Movement: Seiko 6R54 automatic (office GMT)
Power Reserve: 72 hours
Band: Stainless steel bracelet with six-position micro-adjust clasp
Crystal: AR-coated sapphire
Limited Edition?: No
Pricing & Availability
Not limited in edition size, the Seiko Prospex 1968 Heritage Diver’s GMT SPB519 will be available starting June 2025, with pre-orders opening through Seiko Boutiques. It’s priced at €1,900 (approximately $2,136), positioning it in the sweet spot of Seiko’s mid-tier luxury offerings.
Recap
Seiko Prospex 1968 Heritage Diver’s GMT 300m SPB519
Swapping a blue dial for a sunray white, Seiko brings back the 300m GMT diver that was previously a limited edition and makes it a member in its permanent range.
