Introduction This auction presents the Seiko Prospex SBDC083, widely known among collectors as the 3rd generation "Sumo." As part of the prestigious Prospex line, this professional-grade diver's watch is celebrated for its robust construction, oversized case design, and exceptional reliability. It is a quintessential example of Seiko's mastery in creating high-performance tool watches that transition seamlessly from underwater exploration to everyday casual wear. Historical / Era context The "Sumo" nickname originates from its substantial presence on the wrist and the distinctive marker at 12 o'clock, which resembles a sumo wrestler's loincloth (mawashi). This specific model, the SBDC083 (internationally known as SPB101J1), represents a significant technical upgrade over its predecessors. It features the modern Caliber 6R35 movement, which provides an impressive 70-hour power reserve, and is equipped with a sapphire crystal for enhanced durability. Produced in the early 2020s, it remains a pillar of Seiko’s modern diving heritage. Condition The watch is running properly. Case: The 44.5mm stainless steel case maintains its sharp, twisted lug architecture. It shows visible surface scratches and signs of wear consistent with regular use, particularly on the polished sides and the case back. Dial & Bezel: The matte black dial and unidirectional rotating bezel are in good condition. The LumiBrite indices and hands provide exceptional legibility in the dark. The bezel insert shows some light marks from historical use. Crystal: The sapphire crystal is clear and offers excellent protection against scratches. Band: The original Seiko stainless steel bracelet is fitted, showing typical surface marks on the links and clasp. The folding clasp with a diver's extension operates securely. Specifications Brand: Seiko Model: Prospex Sumo Reference: SBDC083 Movement: Automatic (Cal. 6R35) Case material: Stainless Steel Case diameter: 44.5 mm (excluding crown) Dial color: Black Band: Original Seiko stainless steel bracelet Wrist size: Approximately 18.5 cm Accessories: Original inner and outer boxes, instruction manual, warranty card, warranty extension card, product tag, and a copy of the original delivery receipt. Closing note The Seiko Prospex Sumo SBDC083 is a highly respected diver's watch that offers incredible technical specifications and a unique design language. With its ISO-certified water resistance and long-lasting automatic movement, it is ready for its next adventure. Please examine the high-resolution photos carefully to confirm the condition before placing your bid.