W Arch is a cave site located off Irabu Island, Japan, featuring a distinct arch structure that creates sheltered, low-light zones. Divers can explore depths ranging from 5 to 19 metres, with an average depth of 12 metres. The site is accessible by boat and is suitable for beginner divers due to the mild currents. Visibility typically ranges between 15 and 30 metres. Water temperatures remain warm throughout the year, varying from 23 to 30 degrees Celsius. Divers should be aware of lionfish sheltering within the cave structure and along shaded ledges, and maintain buoyancy control to avoid contact with the substrate.

W字アーチ, located off Irabu Island, is a reef and drop-off site defined by its distinctive underwater arched formations. Divers typically explore depths between 10 and 25 metres, with an average depth of 18 metres. Access is by boat, as the site is situated 5000 metres from shore. Visibility generally ranges from 15 to 30 metres. While currents are typically mild, they can strengthen near the drop-off, requiring intermediate skill levels. Divers should maintain buoyancy to avoid contact with sharp coral and rock edges. Protective gear is recommended to prevent stings from jellyfish present in the area. Confirm current conditions with your boat operator before descending.

L Arch is a cave dive located off Irabu Island, characterised by its distinct arch structure. The site ranges in depth from 20 to 40 metres, requiring careful buoyancy control and air management. Access is by boat only, and divers should be prepared for moderate currents that can influence conditions. Due to the depth and cave environment, this site is suited for intermediate divers who can manage their gas planning and depth profiles effectively. Divers should carry a torch and consult with their operator regarding current and visibility before descending. The site requires vigilance to avoid contact with the reef while navigating the cave structures.

Cross Hole is a cave dive located 1000 metres off Irabu Island. The site features an overhead environment with depths ranging from 5 to 24 metres, averaging 15 metres. Visibility is typically between 20 and 30 metres, and currents are generally mild. Divers should maintain precise buoyancy to avoid contact with the cave walls, which are lined with sharp coral and rock. Access is by boat, and divers must remain vigilant for boat traffic when surfacing. While suitable for beginners, the overhead environment requires careful air management. Species recorded around this area include wrasses, anemonefish, hermit crabs, and cauliflower coral.

L-shaped Arch is defined by its dramatic underwater architecture, featuring a cave system and a wall that drops to 36 metres. Located 1000 metres offshore from Irabu Island, this site requires boat access. Divers navigate through the arch and along the wall, where visibility typically ranges from 20 to 40 metres. Moderate currents are common, often allowing for a drift dive through the structure. Due to the overhead environment and depths averaging 25 metres, this site is suitable for intermediate divers with Advanced Open Water certification. Divers should monitor air consumption and depth closely, as the cave section can easily lead to depths exceeding 30 metres.

Shiratori on Irabu Island features a diverse underwater landscape comprising reef, wall, and cave formations. Divers can explore depths ranging from 8 to 30 metres, with an average depth of 15 metres. Visibility typically remains between 20 and 30 metres. The site is suitable for beginners, though moderate currents require careful planning for both shore and boat entries. Divers should be aware of potential surge and swell conditions near the shore. Hazards include sharp coral, strong currents, and the presence of lionfish and sharks. Maintaining neutral buoyancy is essential to avoid contact with the reef and cave structures. Night diving is available at this location.

Hanadai no Ne is a shore-entry reef site located off Irabu Island. The site features a depth range of 2 to 18 metres, with an average depth of 15 metres, making it suitable for beginner divers. Divers can expect mild currents and visibility ranging from 15 to 30 metres. Water temperatures are warm, fluctuating between 23 and 30 degrees Celsius throughout the year. When entering from the shore, exercise caution regarding sharp coral and rocks to avoid injury. Local facilities include air fills, a dive shop, boat charters, and guided tours. Always check for the presence of jellyfish before entering the water.

Snake Hole on Irabu Island is a combined cave and reef site ranging from 5 to 18 metres in depth. The site features an overhead environment that requires intermediate buoyancy control and awareness of the ceiling structure. Visibility is typically between 20 and 30 metres, with mild currents. While the reef supports various marine life, the darker interior recesses of the cave are known to shelter crustaceans and cave-dwelling fish. Access to this site is by boat only. Divers should carry a torch to explore the cave interior effectively. Water temperatures fluctuate between 23 and 30 degrees Celsius throughout the year.