Okishima is a unique freshwater dive site located on Japan's only inhabited island within a freshwater lake. Divers typically access the water from the shore, exploring depths ranging from 3 to 10 metres with an average of 7 metres. The site features a silty bottom and requires awareness of boat traffic and cold water conditions. Visibility can be low, and currents are generally mild. The site is well-supported by local facilities, including a dive shop, equipment rental, air fills, and boat charter services. Divers can expect a typical dive duration of 40 minutes in this distinct freshwater environment.

Chishima is a wall and reef system in Japan that descends from 5 to 40 metres. This site is suited for intermediate divers, offering visibility between 15 and 21 metres. The topography features a distinct drop-off that requires boat access to avoid dangerous surf and shore break. Divers should monitor moderate currents, which can influence drift along the wall. Water temperatures fluctuate between 12 and 23 degrees Celsius throughout the year, necessitating appropriate exposure protection. Typical dives last approximately 40 minutes. Due to the significant depth and current conditions, coordinate all entry and exit logistics with a boat skipper.

Komatsu is a reef and kelp forest site located off the Izu Peninsula in Japan. Reaching depths of up to 17 metres, the site provides a suitable environment for beginner divers. The underwater topography features a mix of reef structures and kelp growth, which support a variety of temperate marine life and invertebrates. Water temperatures fluctuate significantly throughout the year, ranging from 12°C to 27°C, and a dry suit is often recommended during cooler months. Access is by boat only. Divers should remain aware of variable currents and active boat traffic in the area, particularly during surface ascents, and are advised to use a surface marker buoy.