There are two ferry companies which serve Miyajima, and their ticket windows and departure points are next to each other, so be sure you have the correct line. They both operate multiple ferries per day to and from the island, and the price is the same: 170 yen for adults and 80 yen for elementary school students. The ride takes about 10 minutes one way. Each ferry has indoor and outdoor seating, space for cars, and a room for wheelchairs, strollers, or others who have mobility issues.
The JR West Miyajima Ferry offers a route that goes fairly close to the Otorii on the way to Miyajima during high tides. A JR Pass is also valid for the ride. The return trip is a straight path between the ports. Operating times may change, but are approximately 6:25 am to 10:40 pm. The Matsudai Kisen Tourist Ship has slightly nicer facilities, but does not accept the JR Pass. It runs approximately 7:15 am to 8:15 pm. The JR West Miyajima Ferry website is in Japanese: http://www.jr-miyajimaferry.co.jp/
The Miyajima Matsudai Kisen website is in English: http://miyajima-matsudai.co.jp/english/index.html
Access to the ferry ports is not difficult. It is about 25 minutes by train from the JR Hiroshima Station to the JR Miyajimaguchi Station. Both ferry terminals are about a minute walk from there. There is a large souvenir shop with many handmade gifts from both Miyajima and Hiroshima at the ferry terminal, and many restaurants are within walking distance.
photos by: artethgray & variationblogr