Naoshima is great for cycling and there are a few rental places around Miyanoura Port. Cafe Ougiya Rent-a-Cycle is inside the Marine Station at the port. A few electric bikes (¥1000 per day) and scooters (¥1500 per day) are also available. Prices are similar at the other rental shops nearby.
Naoshima 'town bus' minibuses run between Miyanoura, Honmura, and the Benesse Art Site area (Tsutsuji-sō campground stop) in the south once or twice an hour – expect queues during the Setouchi Triennale festival. It costs ¥100 per ride (no change given). From Tsutsuji-sō, there's a free Benesse shuttle, stopping at all the Benesse Art Site museums. In busy seasons buses can fill up quickly, especially towards the end of the day, when people are returning to the port to catch ferries. Be sure to check the timetables and allow enough buffer time.