CITIZEN PROMASTER Mechanical Diver 200m, References NB6021-17E and NB6021-68L

CITIZEN presents a new series of PROMASTER Mechanical Diver watches inspired by a barnacle-covered 1977 Challenge Diver found on an Australian beach.

In 1983, a Challenge Diver was found on Long Reef Beach in Australia. The watch was covered in barnacles after being submerged in the Pacific Ocean, but the movement inside had remained protected from the seawater and was still serviceable. The new PROMASTER Mechanical Diver models take design cues from the original Challenge Diver design, but their external features and the movement inside have been updated for contemporary use.

The sapphire glass has a flat cut top and a domed underside, and the sides of the glass are beveled to provide a chunky, retro look. The watches have a guard-less crown design, and the 41.0 mm diameter is the same as the original model. The case is made of lightweight, scratch-resistant Super Titanium™, and is thinner than the original model to ensure a more comfortable fit on the wrist.

The Cal. 9051 movement in this model uses anti-magnetic materials for the balance spring and surrounding components to boost the magnetic resistance of the watch. It maintains its performance even when placed 1 centimeter from a device emitting a magnetic field of 16,000 A/m. In addition to being resistant to magnetic fields, the watches are also ISO compliant diver’s watches up to 200 meters. They can run for 42 hours when fully wound, with daily accuracy of -10 to +20 seconds.

Technical details

Model name: CITIZEN PROMASTER Mechanical Diver 200m
Model references: NB6021-17E and NB6021-68L

Case
Super Titanium™ (Duratect TIC)
Case diameter: 41.0mm
Case thickness: 12.3mm
Sapphire glass
200m water resistance

Movement
Cal.9051 Mechanical/ Automatic & Manual winding
Accuracy of average -10～+20sec/day
Power reserve: 42 hours (when fully wound)
Frequency: 28,800 vph
24 jewels

Strap
NB6021-17E: Urethane strap
NB6021-68L: Super Titanium™ (Duratect TIC) bracelet