Seiko Prospex Marinemaster 300M Automatic

Seiko Prospex Marinemaster 300M Automatic

Why We Love It

By now, our love for Seiko (new and old) should be apparent. 

From the rare as hen's teeth Hi Beat 6159 to the film-famous 6105 and 6309 models to the economy workhorse SKX007, Japanese watchmakers perfected incredibly well-made tool watches decades ago- and at prices that make the most diehard Swiss watch fans bristle with jealousy.

An update to the Seiko MM300, the SBDX017 was extremely popular while Seiko was producing it. Once it was discontinued, the Seiko community cried out in pain. While Seiko produced a couple limited edition versions in the aftermath, theres just no substitution for the down-to-business original. With its 44mm monocoque case, oversized 'Lumibrite' luminous indicies and and handset, and crisp timing bezel, it is as beautiful (and hefty) as it is functional. The groundbreaking 'DiaSheild' coating which Seiko applied to these models improved its resistance to scratching and corrosion - probably the reason this particular example looks almost unworn. 

At the end of the day, great watch making is great watch making, whether made in Switzerland, Germany, or Japan. As badass as it is reliable, the SBDX017 Marinemaster is a modern classic diver through and through.

The Story

For over 135 years, Seiko has been cranking out innovative and impeccably engineered watches at every price point, from entry level Seiko 5s to world-class high horology pieces under the Grand Seiko brand. Underpinning Seiko's efforts has been the mass production of reliable and accurate movements capable of being paired with a wide array of case and dial configurations. 

Seiko is the piece we always go to when we go out into the field. Whether we're wearing it while hoofing it up a mountain, trudging through the wetlands in search of winged dinner, fishing for brownies or bonefish, or just getting it sandy at the beach, this piece serves a very important role as a timepiece that can take a beating while also giving us watch snobs something to wear that we can be truly proud of.


SKU: AS03320

Stainless steel monocoque case is approximately 44mm (excluding the crown). Seiko Ref. SBDX017. Circa 2017.

Overall Condition: The case is in near mint condition overall showing only slight wear from careful use. Luminous gloss black dial is as new with applied luminous indicies with matching handset. Signed crown.

Includes stainless steel multilink bracelet with ratcheting/locking signed clasp. Also includes inner and outer boxes, papers, spare links, unworn rubber dive strap, hangtags, and warranty tag dated 2017.

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Our Pledge

Analog/Shift stands behind the authenticity of our products in perpetuity.


We back each Analog/Shift vintage timepiece with a one-year mechanical warranty from the date of purchase.


All of our watches include complementary insured shipping within the 50 states. We are happy to hand deliver your purchase in Manhattan or you may pick it up at our showroom.

International Buyers

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