Citizen Promaster Dive "Ecozilla" 48mm Eco-Drive Watch #BJ8057-09X

Model Reference: BJ8057-09X

Overview
The Citizen BJ8057-09X is a specialized, professional-grade diving instrument that belongs to the legendary "Eco-Zilla" lineage. This specific iteration, part of the Metropolitan Adventure series, features a rugged, outdoor-inspired aesthetic with a dark green dial and a grey ion-plated stainless steel case. It is a tool watch of extreme proportions, built to survive the crushing pressures of saturation diving. Known for its "tank-like" construction, it prioritizes structural durability and absolute legibility, making it a favorite for professional divers and enthusiasts who require a watch that can handle the most punishing maritime environments.

Technical Specifications

Case Size: 48mm (Oversized, ultra-robust professional profile)

Case Material: Grey Ion-Plated Stainless Steel (Matte, non-reflective finish with enhanced surface hardness)
Movement: Eco-Drive (Caliber B873; high-torque light-powered movement engineered to move oversized, professional handsets)

Crystal Type: 6mm Extra-Thick Curved Mineral Crystal (Designed with an anti-reflective coating to withstand high underwater pressure)

Water Resistance: 300 Meters (30 ATM / 999 feet) — ISO Compliant for Mixed Gas/Saturation Diving

Dial: Deep forest green dial with oversized, high-contrast luminous indices and a date window at 3 o'clock

Bezel: Unidirectional rotating elapsed-time bezel with deep "gear-tooth" notches for easy grip with diving gloves

Strap: Heavy-duty green polyurethane strap with a stainless steel buckle and an included wetsuit extender

Special Features

Helium-Safe Engineering: The watch is hermetically sealed to be safe for use in saturation diving bells without requiring a separate helium release valve.

9 o'clock Crown (Left-Hand Drive): The screw-down crown is positioned on the left side of the case to protect the back of the hand from impact and to prevent the crown from snagging on equipment.

Extreme Luminous Layout: Features oversized markers and a massive, orange-outlined minute hand, all coated in professional-grade Lume for unmistakable readability in the dark.

Reinforced Case Architecture: The watch lacks traditional lugs; instead, the strap is integrated directly into the circular "capsule" case using a ring-lock system for maximum security.

Metropolitan Adventure Styling: The combination of the grey ion plating and the green strap/dial gives this professional diver a contemporary, tactical look that transitions from deep-sea use to rugged land exploration.

Eco-Drive Power: Powered by any light source, it features a long power reserve and an insufficient charge warning to ensure the watch never stops during a dive.