See Kangaroo Island if you want to come here by ferry.
Regional Express operates 30min flights from Adelaide to Kingscote Airport. Shuttle transport to Kingscote is available, Bookings can be made phoning (08)85532390. A one way ticket is about 80 Australian dollars. Visit http://www.regionalexpress.com.au/ for more details.
Kingscoat is a quite small town, so it's easy to get around by foot.