Sado Island is the second-largest island in terms of area after the main island of Okinawa, and can be reached by ferry from Niigata Port in about 2.5 hours or by jetfoil in about 1 hour. In the summer, the sea is very calm and clear, and the water temperature is warm, making it very popular with divers.

Ogi Port in southern Sado Island offers rich marine life and dynamic terrain. At the “Happy Jizo” point, a Jizo statue rests at 23m, where divers leave coins for safety prayers. With drop-offs and reef zones, it’s a favorite for topography enthusiasts.

Ryuoh-do Cave on Sado Island’s Ogi Peninsula is a large sea cave nicknamed the “Blue Cave” for its clear waters and glowing blue light. Popular for diving and sea kayaking, it hosts sea slugs, seahorses, and more, offering a magical experience for beginners to intermediate divers.

Banjin Beach in Kashiwazaki, faces the Sea of Japan and offers calm conditions with diverse underwater scenery. With a max depth of 10m and beach entry, it’s great for all levels. Sandy, rocky areas and seaweed forests host seahorses, nudibranchs, dungeness corals, jellyfish and schools of horse mackerel.

Yotsushima, or the Four Islands, is a rare “Jetty Dive” spot in Japan, located around Ruzaoan Island. Entry is from a ferry pier, just 5 minutes by boat. The harbor has parking, water, and flush toilets. The reefs host abundant marine life, with frequent sightings of large schools of fish.

Kamo Aquarium in Tsuruoka City, Yamagata Prefecture, is famous for having the world’s largest jellyfish display. The diving area offers free parking, clean flush toilets, and calm conditions with depths of 8–12m. Its gentle environment and variety of sites make it ideal for beginners.

The diving pool attached to the store is a true diving pool designed exclusively for diving training. A large circulation clean system operates 24 hours a day to keep the water hygienic and clear. Water quality is also controlled by human hands to maintain clean water quality at all times. Shower rooms are adjacent and locker rooms are available free of charge.

Tobishima is located 39 km off the coast of Sakata City, and in August, the clarity is 20 to 30 meters. You can see the terrain dropping to 40 meters vertically. There are also a variety of corals and isoflavas, which are rare in the Tohoku region.

This is the border between Toyama and Niigata prefectures. The Oshirachi Beach is a cliff facing the open ocean, and the clarity is good, sometimes exceeding 20 meters from June to September. There are many large roots and rocks in the water, as well as arches and crevasses to enjoy the terrain.

The Okinose W-Arch is situated on the Etchu-Miyazaki Coast, at the easternmost tip of Toyama Prefecture. Located approximately 1 kilometer offshore, it faces the open ocean. The water remains clear from spring through summer, although occasional strong currents can be encountered. The water depth here is about 15 meters, and the presence of two arches side by side is an exceedingly rare occurrence on the Sea of Japan side. According to local legend, an ancient shrine once stood in this area, making it known as a power spot. Visiting this site is highly recommended.