Deep Dive Heritage The Rolex Sea-Dweller was developed in collaboration with professional divers to meet the challenges of saturation diving. With its helium escape valve and robust construction, it has long been a benchmark in deep-sea watchmaking. The Sea-Dweller is a tool watch that embodies Rolexs pioneering spirit beneath the waves. Classic Utility This reference 16600 features a 40mm case and a black dial with luminous hour markers for visibility in dark underwater environments. The unidirectional bezel is calibrated for 60 minutes, supporting precise dive timing. Powered by the calibre 3135 automatic movement, it offers a power reserve of approximately 48 hours. The Oyster bracelet is fitted with a Fliplock extension and Oysterlock clasp, ensuring a secure fit during underwater missions.