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SEIKO PROSPEX – Pro Marine Master 300m SLA023J1


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Seiko Prospex Pro Marine Master 300m Automatic Men’s Stainless Steel Bracelet Watch

Available from the following watch specialists
Included with product:
* Branded Packaging
* Completed Warranty
* Free Bracelet Sizing
* Free Gift Wrapping

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First produced in 1968, the stunning Seiko Marine Master has been re-imagined for today. Modelled on the original Marine Master MM300, the modern Seiko Prospex Pro Marine Master is certain to impress.

Water resistant to 300 m/1000 ft the Marine Master is built for saturation diving. Made for professional divers, it is deliberately uncomplicated. This allows the quality of the movement and the ergonomic case and bracelet to shine through.  With a one piece structure, the heavy-duty brushed stainless steel case is 44.3mm in diameter. The deep blue dial has high-visibility hour markers and hands coated in Lumibrite. A legible minute track is also at the extreme edge. Surrounding the dial, there is a blue ceramic uni-directional turning bezel in dark blue.

Equipped with an automatic 8L35 calibre movement, the Seiko Prospex Pro Marine Master is accurate to +15 to -10 seconds per day with a power reserve of approximately 50 hours. Presented in a box with an additional silicone strap, this is a first-rate professional divers watch. For complete peace of mind, it is covered by a two year manufacturer’s warranty.

  • Automatic movement calibre 8L35 with manual winding capacity
  • 26 jewels
  • Accurate to +15 to -10 seconds per day
  • Duration: approx. 50 hours
  • Stainless steel case, one piece structure, ceramic unidirectional turning bezel
  • Case dimensions: 44.3mm diameter, 15.4mm deep
  • Date display
  • Stop second hand function
  • Blue dial – indexes and hands with Lumibrite
  • Stainless steel bracelet, three-fold clasp with secure lock, push button release, solid & slide adjuster
  • Additional silicone strap included
  • Sapphire crystal – anti-reflective coating on inner surface
  • Screw-down crown
  • Water resistant 30 bar (300m)/1000ft – for saturation diving
  • Two Year Manufacturer’s Warranty
Additional information

Seiko Prospex



Movement Type

Automatic Mechanical

Case Shape


Dial Colour


Material Type

Stainless Steel

Strap Type

Metal Bracelet

Water Resistance


Based on 149 reviews
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  1. Elgharabawy Mostafa

    Verified reviewVerified review - view originalExternal link | saSaudi Arabia

    Extremely Professional Service, exact item received in a well packaged parcel, I would definitely return back 🙂

  2. Anonymous

    Verified reviewVerified review - view originalExternal link | gbEngland, United Kingdom

    Very straightforward ordering and delivered timeously!

  3. Caroline C.

    Verified reviewVerified review - view originalExternal link | gbEngland, United Kingdom

    Quick service and great communication. Strap arrived as promised and well packaged. Many thanks

  4. Anonymous

    Verified reviewVerified review - view originalExternal link | gbUnited Kingdom

    The website is easy to use and was able to order without any problem, customer service was good.

  5. Malcolm Bruce

    Verified reviewVerified review - view originalExternal link | gbScotland, United Kingdom

    From the very beginning of making an enquiry to placing my order for an Oris watch strap I was looked after by Suzie in a professional and friendly manner. I would recommend watch specialists without hesitation to my family and friends. 10/10 thank you for a brilliant experience 😊

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