Description
SEIKO PROSPEX Diver Scuba SUMO SBDC175
The SEIKO PROSPEX SBDC175 is a Japanese Domestic Market mechanical diver’s watch from the Diver Scuba collection. Known by the enthusiast nickname “SUMO,” this Core Shop model combines a blue gradient dial with a ceramic bezel display plate, a sapphire crystal and a stainless steel case and bracelet protected by SEIKO’s DiaShield surface treatment.
Blue Gradient Dial Inspired by the Night Sea
The blue gradient dial is designed to evoke a calm ocean illuminated by moonlight. Its shifting blue tones add depth while retaining the clear, functional layout expected of a mechanical diver’s watch. A date window is positioned at 3 o’clock.
LumiBrite is applied to the hands, indexes and bezel marker to support visibility in dark environments. The broad hands and prominent applied indexes provide strong contrast against the blue dial.
Automatic Caliber 6R35
The SBDC175 is powered by SEIKO’s Caliber 6R35 mechanical movement. It winds automatically through wrist movement and can also be wound manually through the crown. The movement operates at 21,600 vibrations per hour, contains 24 jewels and provides approximately 70 hours of power reserve when fully wound.
A stop-seconds function allows the seconds hand to be halted when setting the time. SEIKO specifies an accuracy range of +25 to −15 seconds per day when the watch is worn on the wrist within a temperature range of 5°C to 35°C.
DiaShield Case and Ceramic Bezel
The stainless steel case is protected by DiaShield, a surface treatment designed to improve resistance to everyday scratches. It measures 52.6 mm in length, 45.0 mm in width and 13.4 mm in thickness.
The unidirectional rotating bezel uses a ceramic display plate with a glossy, scratch-resistant surface. A sapphire crystal with an anti-reflective coating on the inner surface protects the dial while supporting clear visibility.
Mechanical Diver’s Watch Construction
The SBDC175 is rated for 200 m air-diving water resistance. Its diving-oriented construction includes a screw-down crown, screw case back, unidirectional rotating bezel and a secure-lock clasp with a diver’s extension mechanism.
The stainless steel bracelet also features DiaShield and accommodates wrists measuring up to approximately 195 mm. The complete watch weighs approximately 190 g.
Japanese Core Shop Model
SBDC175 is the reference assigned to the Japanese domestic market and was offered through SEIKO Global Brand Core Shops. Core Shop exclusivity identifies its authorized Japanese retail channel; it does not mean that the watch is a numbered Limited Edition.
Japanese retail information identifies the completed watch as manufactured in Japan. Japanese Domestic Market status and country of manufacture are separate product classifications.
Key Highlights
- Blue gradient dial inspired by a moonlit night sea
- Caliber 6R35 automatic movement with manual winding
- Approximately 70-hour power reserve
- 45.0 mm stainless steel case with DiaShield
- Ceramic unidirectional bezel display plate
- Sapphire crystal with inner anti-reflective coating
- 200 m air-diving water resistance
- Screw-down crown and screw case back
- Stainless steel bracelet with diver’s extension
- Japanese Domestic Market Core Shop model
Product Specifications
| Brand / Collection | SEIKO PROSPEX |
|---|---|
| Series | Diver Scuba |
| Model | SBDC175 |
| Nickname | SUMO |
| Market | Japanese Domestic Market |
| Country of Manufacture | Japan |
| Edition | SEIKO Global Brand Core Shop exclusive model |
| Watch Type | Mechanical diver’s watch |
| Display | Analog with date |
| Dial Color | Blue gradient |
| Case Dimensions | 52.6 mm length × 45.0 mm width × 13.4 mm thickness |
| Weight | Approximately 190 g |
| Case Material | Stainless steel with DiaShield |
| Bezel | Unidirectional rotating bezel with ceramic display plate |
| Crystal | Sapphire crystal with inner anti-reflective coating |
| Crown | Screw-down crown |
| Case-Back | Screw case back |
| Bracelet | Stainless steel with DiaShield |
| Band Width | 20 mm |
| Clasp | Push-button three-fold secure-lock clasp with diver’s extension |
| Compatible Wrist Size | Up to approximately 195 mm |
| Movement Type | Mechanical automatic with manual winding |
| Caliber | 6R35 |
| Power Reserve | Approximately 70 hours when fully wound |
| Frequency | 21,600 vibrations per hour (6 vibrations per second) |
| Jewels | 24 jewels |
| Accuracy | +25 to −15 seconds per day when worn on the wrist between 5°C and 35°C |
| Functions | Stop-seconds function; date display |
| Luminescence | LumiBrite on the hands, indexes and bezel marker |
| Water Resistance | 200 m for air diving |
| Magnetic Resistance | Type 1 magnetic resistance |
| Release Date | August 19, 2022 |
| JAN Code | 4954628462428 |