With a circumference of 75 kilometers, Iriomote Island is the prefecture’s second largest island after Okinawa. 90% of Iriomote is virgin subtropical forest. With the Iriomote wildcat and many other rare and unique animals and plants, Iriomote is called the Galapagos of the Pacific. Half the island is included in the Iriomote National Park. The park is a national preservation district and it is chock full of protected species. At one time, malaria and other endemic diseases were rampant in Iriomote and it was a hard and dangerous environment to live in. Development progressed, though, and now the island is a top destination for marine sports and ecotourism.
Two ports on the island have services from Ishigaki, operated by Anei Kanko, Yaeyama Kanko Ferry, Hirata Kanko and Ishigaki Dream Kanko Ferry.
Ohara, on the east coast, is the busiest port on the island and accessible in all but the very worst weather. Both Anei and Yaeyama and Ishigaki Dream operate boats roughly hourly for a fixed ￥1540 and take about 35 minutes.
As of summer 2006, Funaura port is no longer used by regular ferry traffic. Anei and Yaeyama boats both service nearby Uehara. Both services cost ￥2000 and take about 40 minutes.
Note that northwest coast services are subject to cancellation (欠航 kekko) if there is a strong north wind, which happens particularly frequently in the winter. In this case your ￥2000 will get you to Ohara by boat and then a free bus transfer to anywhere between Ohara and Shirahama.