Atami Kosoga Cave

This dive site, Atami Kosoga Cave, is a unique and accessible underwater cavern located in Atami, Shizuoka, Japan. Measuring approximately 40 meters long, this semi-enclosed cave is found at depths between 6 to 12 meters, making it exceptionally beginner-friendly. Its most striking feature is an open ceiling that allows natural sunlight to penetrate, creating an ethereal blue gradation throughout the cavern. Accessible just 10 minutes by boat from Atami Port, the site offers an easy and rewarding dive experience. Within the cave and surrounding areas, divers can observe vibrant marine life. Schools of snappers, rockfish, and mackerel are frequently encountered, often moving in large formations that appear like underwater rivers. The sandy bottoms adjacent to the cave are known to host larger bottom dwellers, including various sharks and bullhead sharks, adding an exciting element for observant divers. The best time to visit Atami Kosoga Cave is during its operational season, which runs from November to April. This period likely offers optimal conditions for the stunning light effects and marine encounters described. Its shallow depths and wide spaces make it highly suitable for both snorkelers and freedivers, offering a captivating experience for all levels of underwater enthusiasts without the need for extensive training or deep diving skills.