Benten Island offers a combination of natural reef and artificial reef structures located 500 metres from shore. The site ranges in depth from 10 to 25 metres, with the most notable terrain found in the shallower sections where the two reef types meet. Access is by boat only. Divers should be prepared for moderate currents and visibility averaging 10 metres. Water temperatures fluctuate between 9 and 22 degrees Celsius due to the mixing of the Kuroshio and Oyashio currents, often resulting in thermoclines. Hazards include cold water, entanglement risks near artificial structures, and potential surf. A drysuit or thick wetsuit with a hood is recommended for cooler months.

High Bridge is a shallow reef site located off the Izu Peninsula in Japan. Accessible only by boat, this site is well-suited to newly certified divers looking to build confidence in open water. The reef environment supports a variety of reef fish and invertebrates typical of the region. Conditions at the site are variable, with currents that can change between visits. Water temperatures fluctuate significantly throughout the year, ranging from 9C in March to 25C in August. Guided tours are available through the local dive shop to assist with dive planning and to provide advice on appropriate wetsuit thickness for the current conditions.