This dive site, Nagashima Kaiba 1, is situated around Cape Shakotan, the northernmost tip of northwestern Hokkaido, Japan. Celebrated as Hokkaido's sole underwater park and recognized as one of Japan’s 100 best sandy beaches, it offers a visually stunning environment. Navigation likely involves exploring the rich topography of this protected marine area, which holds significant natural beauty and ecological importance.
The site is teeming with diverse marine life. Notably, large pelagic species are a highlight, with tuna often sighted around September. From June, massive schools of tens of thousands of headliners and bowhead whales, measuring up to 12-3 meters, can be observed offshore. Around April, killer whales are known to move in schools through the area, adding to the spectacular marine encounters.
The best time to visit for specific animal sightings varies: killer whales in April, whales and headliners from June, and tuna in September. This site is excellent for both divers and freedivers due to its relatively shallow depths (average 9m, max 18m) and abundant marine life. Snorkelers will also enjoy the vibrant underwater park from the surface.
