Seiko - 2017 Marinemaster Professional 300 SBDX017

WHAT WE LOVE:

The Seiko Marinemaster Professional 300 — the MM300 — is the watch that sits above the SKX and Turtle families and below Grand Seiko, at a price point where Seiko applied genuinely different standards. The monocoque one-piece case is machined from a single billet of Dia-Shield-coated stainless steel, its Zaratsu-polished surfaces achieving the distortion-free mirror quality that is typically associated with Grand Seiko at several times the price. The case construction, the bracelet, the Calibre 8L35 movement — each element reflects a watch built to amazing specification.

The SBDX017 was the updated reference that replaced the SBDX001 in 2015, and it was discontinued when Seiko transitioned the Marinemaster Professional line to the SLA series with sapphire crystal and ceramic bezel. The SBDX017 carries Hardlex rather than sapphire — a period-correct choice that gives the watch a slightly different optical character from the current generation — and the lollypop seconds hand, the matte black dial with its broad luminous hands, and the overall visual weight of the watch are details that the collector community values precisely because the current SLA series moved away from them. A 2017 SBDX017 is a fully mature example from the middle of the reference's production, before the transition — it comes complete with box, papers and spare rubber strap.

WHAT'S INSIDE

The SBDX017 is powered by the Seiko Calibre 8L35 — a 26-jewel in-house automatic movement with manual winding capability and hacking seconds, beating at 28,800 vibrations per hour with a 50-hour power reserve. The 8L35 is an undecorated variant of the movement architecture used in Grand Seiko's mechanical calibres, built to tighter tolerances than the standard Seiko production movements and typically performing to +15/-10 seconds per day. The Dia-Shield-coated monocoque case provides 300-metre water resistance via the screw-down offset crown.

FIVEFORTYFIVE SIX MONTHS WARRANTY