U-Boat Darkmoon Oil Immersion Men’s Blue Watch

U-Boat Darkmoon Blue Soleil Ref. 9021/C brings colour and innovation together in a refined 41.5mm format, combining U-Boat’s oil immersion technology with a striking blue soleil dial for exceptional depth and clarity.

Powered by the Swiss Ronda 712.3 quartz movement, lubricated in an oil bath, this model delivers precise and reliable timekeeping with a minimalist display of hours and minutes. The visible air bubble compensates for temperature variations, underlining the Darkmoon’s distinctive technical character.

The stainless steel case is completely oil-filled to create the illusion of an absent crystal and enhance legibility, complemented by a left-positioned crown and curved sapphire crystal. Finished with a durable black vulcanised rubber strap featuring an easy-release system and steel buckle, this Darkmoon offers modern design with unmistakable U-Boat identity.

Questions & Answers

• What makes the oil immersion design unique? The oil-filled case enhances dial depth and legibility, creating the illusion of no crystal.
• What movement powers this watch? It uses a Swiss Ronda 712.3 quartz movement lubricated in an oil bath.
• Is the dial luminous? Yes, the hands, numbers, and indexes are treated with beige Superluminova.
• Is the battery easy to replace? Yes, the locking ring system allows quick battery replacement.
• Is it suitable for everyday wear? Yes, its robust stainless steel case and rubber strap make it ideal for daily use.