Pre-Owned Seiko Marine Master Professional 300M – SBDX001 (8L35)
A Iconic Seiko Diver – Good/Fair Condition

Up for sale is my Seiko Marine Master Professional 300M (SBDX001), a standout piece that has been part of my collection for several years. It’s a watch I’ve genuinely enjoyed owning—bold presence, iconic design, and one of Seiko’s most respected professional divers. I’m moving my collection in a different direction, and this one simply isn’t getting the wrist time it deserves.

The watch has not been serviced, but it continues to keep fantastic time. It comes on the original stainless steel bracelet and includes the manual, papers and Seiko Prospex box.

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Price: $1950 USD

Condition
Keeps excellent time

Light, honest wear consistent with careful use

Crystal clean

Bracelet and clasp in strong condition with a few light scratches.

Includes Prospex box + manual

Why This Model Matters
The SBDX001 is one of Seiko’s most sought‑after professional divers. It features the premium 8L35 movement, built at the Shizuku‑ishi Watch Studio—the same facility responsible for Grand Seiko mechanical calibers. It’s a true tool watch with serious pedigree.

Specifications
Model: Seiko Marine Master Professional 300M – SBDX001

Movement: 8L35 automatic, 26 jewels, hacking + hand‑winding

Power Reserve: 50 hours

Case: One‑piece stainless steel monocoque

Diameter: 44.3 mm (without crown)

Thickness: 14.6 mm

Crystal: Dual‑curved Hardlex with non‑reflective upper coating

Bezel: Uni‑directional, anti‑reverse rotation

Crown: Screw‑down

Lume: Lumibrite hands and markers

Water Resistance: 300 m (professional diver rating)

Bracelet: Stainless steel with double‑locking fold‑over clasp + diver extension

Anti‑magnetic: Yes