Ugan-bishi is a massive coral reef system located off the southeast coast of Aka Island. This site features extensive hard coral gardens and is accessible exclusively by boat. Divers and snorkellers should be aware that the site is subject to moderate to strong currents, making it suitable for advanced divers. The depth ranges from 7 to 40 metres, offering a varied topography across the reef structure. Water temperatures fluctuate between 22C and 28C throughout the year. Due to the nature of the currents and the depth profile, this location requires careful planning and experience.

Hatenohama, specifically the Naka-no-hama section, is a 7km sandbar composed of three islets. This site features white sand bottoms interspersed with coral patches, creating a shallow environment suitable for snorkelling. Depths typically range from 1m to 5m, with an average of 3m. Access is exclusively by boat, as the site is located 5km from the shore. Conditions vary, with visibility generally between 15m and 30m and moderate currents. Hazards include sharp coral and strong currents. Facilities available at the site include toilets, showers, and a dive shop. The site is rated 5/5 for snorkelling and is suitable for beginners.

Umagai is a wall and reef site located off Aka Island, Japan, featuring a dramatic drop-off that descends from 7 metres to 40 metres. The site offers visibility between 20 and 30 metres, supported by moderate currents. Divers should exercise caution near the wall face, as surge can push swimmers toward sharp coral and rock edges. While the site is accessible to beginners, the significant depth requires careful buoyancy control and monitoring of depth gauges. Boat access is required for all dives. Protective gear is recommended to prevent injury from sharp substrate. Divers should consult with their boat operator regarding current conditions before entry to ensure a manageable experience.

Manta Station is a reef site located 4000 metres off Aka Island in the Kerama Islands. This site is primarily accessed by boat and is suitable for advanced snorkelers. The topography features a reef environment with depths ranging from 7 to 18 metres, averaging 8 metres. Water temperatures remain warm throughout the year, ranging between 22C and 29C. Divers and snorkelers should be aware of boat traffic and surf conditions in the area. The site supports a variety of reef fish and invertebrates typical of the subtropical Okinawa Islands habitat.

Tatami-ishi on Ojima Island is a shallow reef site known for its distinctive hexagonal rock formations. Accessible via shore entry, the site is suitable for beginners and families, offering snorkeling opportunities within tide pools and crevices at high tide. Depths range from 1 to 5 metres, with an average of 3 metres. Visibility typically varies between 10 and 30 metres, and currents are generally mild. Water temperatures fluctuate between 22C and 29C throughout the year. Parking facilities are available for visitors at this location.

Imazuni is a reef and drop-off site located off Aka Island in the Kerama Islands. The topography features a shallow reef starting at 7 metres that transitions into a wall descending to 30 metres. Visibility is consistently 23 metres. Divers should expect a moderate current running along the drop-off, which requires careful management; it is recommended to stay near the reef and use the wall for shelter. The site is suitable for beginners and supports night diving. The habitat supports a variety of reef fish and invertebrates typical of the Okinawa Islands region.

Eef Beach (Central) on Aka Island is a 2km stretch of white sand beach. The site features an inner lagoon with sandy bottom conditions, protected by an outer reef that keeps the water calm. Small coral heads are located closer to the reef edge. This site is suitable for beginners and offers shore access for snorkelling. Water temperatures range from 22C in February to 29C between July and September. Due to the protected nature of the lagoon, it provides a calm environment for those looking to snorkel in the Kerama Islands.

Tonbara is a reef and pinnacle site located off Aka Island, Japan. The topography features a deep structure ranging from 15 to 40 metres, with an average depth of 25 metres. This boat-only site is characterised by strong currents, which require careful planning and coordination with local operators. Divers should aim to dive during slack water to manage the current effectively. Visibility at the site typically fluctuates between 10 and 25 metres. Due to the depth and the potential for significant current, this site is suited for intermediate and advanced divers. Always monitor local conditions closely before entry and adhere to established boat safety procedures.