SBDX017

The Seiko SBDX017 is the final iteration of the legendary Marine Master 300 before Seiko transitioned to the Prospex logo, making it a favorite among collectors who value the classic dial layout and “Marinemaster” text. This model continues the lineage that began with the SBDX001, offering the same monobloc case construction and professional-grade dive heritage, but with subtle upgrades in finishing and materials. Its place as the last of its kind gives it special appeal for those seeking a pure, pre-Prospex aesthetic in Seiko’s high-end diver range.

Inside, the SBDX017 runs the in-house 8L35 automatic movement, prized for its Grand Seiko lineage and robust performance. The 44.3mm stainless steel case is paired with a sapphire crystal and 300m water resistance, making it suitable for real diving as well as daily wear. The dial’s improved anti-magnetic properties and enhanced LumiBrite lume distinguish it from its predecessors, while the solid caseback and screw-down crown maintain the tool-watch DNA.

When shopping for an SBDX017, look for full sets with original bracelet, rubber strap, and box/papers, as completeness impacts value. Pricing often reflects condition, bracelet stretch, and whether the watch has been serviced—factory-fresh lume and unpolished cases command a premium. Since the SBDX017 was produced for a relatively short period (2015–2018), it’s less common than the SBDX001, and its status as the last “Marinemaster” signed dial makes it especially desirable for collectors focused on Seiko’s classic dive era.