Seiko Prospex Automatic Diver Watch SBDC031 "Black Sumo" Scuba 200m Date Indicator - S.S. Case

Watch Overview

This is a modern 2017 Seiko Prospex Diver Automatic men’s wristwatch, reference SBDC031, also known as the “Black Sumo”, a robust and reliable Japanese-made dive watch designed for serious underwater performance and everyday wear. This model features a classic diver aesthetic with professional-grade specifications, built for both durability and comfort.

Powered by the Seiko 6R15A self-winding movement, it features 24 jewels, a sweeping seconds hand, hacking seconds, and a date indicator with quick-set date function at 3 o’clock. Beating at a frequency of 21,600 vibrations per hour, the movement offers a generous 70-hour power reserve, ensuring long-lasting precision with minimal winding.

It features a bold 45mm stainless steel case with a black unidirectional rotating bezel, a screw-down crown, and a sapphire crystal for superior scratch resistance. The dial is a clean, deep black with luminous silver-tone markers and hands, offering strong legibility in low-light conditions. It is rater to Scuba 200-meter water resistance. This watch is fitted with a comfortable black rubber two-piece strap. It is in good condition, showing light wear consistent with regular use, and has been fully inspected and authenticated by our in-house watchmaker. It is running accurately.

Product Details

General Specifications

• Brand: Seiko
• Type: Wristwatch
• Model: Prospex Diver Automatic - "Black Sumo"
• Reference: SBDC031 - 6R15-00G0
• Year / Era: 2017 - Modern
• Gender: Men's
• Country of Manufacture: Japan

Dial & Display

• Display: Analog
• Color: Black
• Features: Luminous Silver-tone index hour markers, white minute/second track around the outer rim, and luminous matching hands. Date window at 3 o'clock.

Movement

• Type: Automatic
• Caliber: Seiko 6R35A
• Jewels: 24
• Movement Functions:
  • Self-winding
  • Central hours and minutes
  • Sweep Seconds
  • Hacking-Seconds
  • Date calendar with quick-set
• Power Reserve: 70-hours
• Frequency: 21,600 vph

Case & Band

• Material: Stainless Steel
• Case Shape: Round
• Bezel: Black. Uni-directional rotating
• Crystal: Sapphire
• Back: Screw-back
• Crown: Signed screw-down crown at 4 o'clock position
• Water Resistance: 200 meters (660 feet / 20 ATM / 20 bar)
• Band Type: Black rubber two-piece strap
• Case Back Markings: Seiko AIR Diver's 200m - 6R15-00G0 - 7900120 - Seiko Time Corp. China Case

Case Measurements (mm)

• Case Size: 45
• Case Thickness: 13
• Lug Width: 20
• Band Width: 20

Additional Info

• Box & Papers: NO
• Condition: The watch is in good condition, some signs of wear consistent with use, a solid case, bezel and nice dial.
• Extras: This timepiece has been fully inspected and authenticated by our in-house watchmaker, confirming that it runs accurately.

History & Legacy of Seiko

Seiko Watch Corporation is a renowned Japanese company specializing in the manufacture of wristwatches, clocks, and electronic devices. Founded in 1881 by Kintaro Hattori in Tokyo under the original name Seikosha, the company began by producing high-quality clocks before expanding into pocket watches in 1895. Over the decades, Seiko has built a global reputation for innovation, precision, and reliability—making it an excellent choice for those who value accuracy, durability, and timeless craftsmanship in their timepieces.

 

About Second Hand Horology

At SECOND HAND HOROLOGY, we offer a curated selection of watches ranging from vintage to modern, including both brand-new and pre-owned timepieces. We’re committed to quality, accuracy, and integrity. Our listings feature:

Professional, unedited photography and clear, transparent descriptions. Every watch is thoroughly inspected and securely packaged to ensure a confident, seamless buying experience.

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