Crystal Park is a shallow reef site located off Irabu Island, Japan. The site features a depth range of 8 to 11 metres, with an average depth of 10 metres, making it suitable for beginner divers. Visibility typically varies between 10 and 30 metres, allowing for clear views of the reef structure. The site experiences mild currents, which facilitate relaxed observation of the reef. Access is exclusively by boat. Water temperatures range from 23 to 30 degrees Celsius throughout the year. Species recorded around this area include wrasses, hermit crabs, giant morays, titan triggerfish, sea kraits, anemonefish, and various invertebrates such as clams and nudibranchs.

Twin Cave on Shimoji Island features two adjacent cave formations that provide a sheltered environment for divers. The site ranges in depth from 5 to 19 metres, with an average depth of 15 metres, making it suitable for beginners. Visibility typically fluctuates between 10 and 30 metres, and the mild current ensures a relaxed experience. Access to this site is by boat only. Divers should carry a torch to explore the darker recesses of the cave walls and entrances. The site is best visited in April, though boat bookings should be arranged well in advance due to high demand during this period.

Naruhodo The Cave is a boat-access dive located off Shimoji Island. The site features an overhead environment with depths ranging from 15 to 18 metres. Divers should be prepared for variable visibility and must maintain careful buoyancy control to avoid contact with the cave structure. Currents at the site are generally mild, though the overhead nature of the cave requires constant awareness of surroundings and exit paths. Due to the limited natural light in deeper sections, carrying both a primary and backup torch is essential. This site is suitable for beginners, though comfort in confined spaces is necessary for navigating the cave environment safely.

Marine Lake on Shimoji Island offers a unique combination of cave and reef diving within a sheltered, land-locked marine environment. Divers can explore depths ranging from 5 to 17 metres, where mild currents generally prevail. The site is accessible via shore entry and is suitable for newly certified divers. Visibility at this location is variable, so checking local conditions before a dive is recommended. Night diving is permitted, providing an opportunity to observe the site under different conditions. Due to the presence of jellyfish, wearing full body protection such as a full wetsuit or skin suit is essential for all divers.

Nakanoshima Hole is a cave and reef system located off Shimoji Island. The site features depths ranging from 5 to 26 metres, requiring boat access. Divers and snorkellers should be prepared for strong currents that can shift direction within the cave structure. Due to the overhead environment and current conditions, this site is suited for intermediate divers with strong buoyancy control skills. Water temperatures fluctuate between 23 and 30 degrees Celsius throughout the year. Visibility is variable, and it is recommended to consult with boat operators regarding current conditions before descent. Always remain close to your guide when navigating the cave sections.

Nakanoshima Channel on Shimoji Island offers a diverse marine environment featuring reef, cave, and drift diving. Divers can explore depths ranging from 5 to 20 metres, with an average depth of 15 metres. The site is accessible only by boat, and the mild currents make it suitable for beginners. Visibility typically ranges between 10 and 30 metres. Water temperatures are warm, fluctuating between 23 and 30 degrees Celsius throughout the year. Divers should exercise caution regarding surge and swell conditions, and avoid contact with sharp coral and rocks while navigating the reef and cave sections.

Antonio Gaudi is a shore-entry reef dive located at Shimoji Island. The site offers a manageable environment suitable for divers of various certification levels, featuring shallow and generally calm conditions. Water temperatures fluctuate between 23C in the winter and 30C during the peak of summer, typically requiring only a light wetsuit. Because current and visibility can vary significantly, it is essential to consult with a local dive shop to confirm current conditions and plan entry timing before heading out. As there are no confirmed facilities at the site, divers should arrive fully prepared with all necessary equipment.

Mini Grotto on Shimoji Island is a cave site accessible by boat. The topography features an overhead environment with depths ranging from the surface down to 20 metres. Conditions are generally mild, though divers and snorkellers must maintain awareness of the overhead structure and control their buoyancy while navigating the cave. The site is suitable for beginners, provided they remain within their comfort levels regarding the cavern depth. Water temperatures fluctuate between 23 and 30 degrees Celsius throughout the year. Hazards include the overhead environment and the presence of lionfish; maintain a safe distance from these fish to avoid stings while exploring the shaded ledges.