Seiko Prospex Alpinist Blue JDM HBC008J Automatic Watch (39.5 mm, Caliber 6R54 72h, AR-Coated Sapphire Crystal, Built-in Compass, 200 m WR, DiaShield)

Description and Key Features

The Seiko Prospex Alpinist HBC008J is an instrumental reference model distributed exclusively in the JDM (Japanese Domestic Market) and manufactured entirely in Japan. This version stands out for its deep blue dial with a matching leather strap, combined with the iconic rotating inner bezel featuring a functional compass, operated by the second crown located at the 4 o’clock position.

It is powered by the Seiko Caliber 6R54, a in-house mechanical movement that provides an extended power reserve of 72 full hours (3 days of runtime), manual winding, and a seconds-stop function. Its solid steel case (39.5 mm in diameter and 13.6 mm thick) features the patented hardened coating DiaShield (Diamond Shield), protecting the metal surface from scratches and everyday wear and tear. It features a sapphire crystal with an anti-reflective coating, a screw-down crown for water resistance of 200 meters (20 bar), and a genuine cowhide leather strap with a folding clasp.

Technical Specifications

Feature Technical Detail
Brand / Collection Seiko Prospex Land – Alpinist
Reference HBC008J (JDM – Japanese Domestic Market)
Manufacturing Made in Japan
Movement Japanese-made mechanical automatic (hand-wound with seconds stop)
Caliber Seiko 6R54 (21,600 vibrations per hour)
Power Reserve Approx. 72 hours (3 days of power reserve)
Case Diameter 39.5 mm (without crown)
Case Thickness 13.6 mm
Case Material Solid stainless steel with DiaShield hardened coating (Super-hard coating)
Front Crystal Sapphire with anti-reflective coating on the inner surface
Dial Blue with applied hour markers and faceted hands
Luminescence High-visibility LumiBrite on hands and hour markers
Bezel / Additional Feature Rotating inner ring with cardinal direction scale (Compass) operated by the crown at the 4 o’clock position
Water Resistance 200 Meters / 20 Bar (screw-down crown)
Main Crown Screw-down at 3 o’clock
Case Back Screw-down with official series markings
Magnetic Resistance Anti-magnetic shielding (4,800 A/m)
Strap: Genuine blue cowhide leather
Closure: Stainless steel folding clasp with safety pushers
Calendar: Date window

Key Selling Points

• JDM Edition Made in Japan: Produced for the domestic Japanese market, a distinguishing factor that drives high demand and appreciation compared to standard global distribution models.
• 6R54 Mechanical Movement with 3-Day Power Reserve (72h): Allows you to switch between watches over the weekend without needing to reset the time or wind the watch on Monday.
• DiaShield Anti-Scratch Coating: A hardened coating that significantly increases scratch resistance on both polished and satin-finished steel, preserving the factory finish through daily use.
• Sapphire Crystal and Instrument-Grade Water Resistance (200 m / 20 Bar): A screw-down crown and dive watch-grade tolerances ensure it is suitable for nautical use, swimming, and bathing without the risk of water ingress.
• Internal Bezel with Solar Compass: A functional mechanical instrument that allows you to determine true north outdoors by aligning the hour hand with the sun.
• 39.5 mm Balanced Case: A standard size for medium-sized wrists and versatile use