The most common way to arrive and depart by sea is by private yacht. It runs during business hours on weekdays, half the day on Saturday and not at all on Sunday. There are also taxis available on Rarotonga and Atiu. You can rent a car on Rarotonga, Aitutaki and some of the other islands, but nothing would be more than a half hour away. Keep your wits about you on Friday and Saturday nights, when there's heavy drinking going on.
Bicycles are a good way to get around and readily available for hire.
The fastest way to get between the islands is by plane. Via 18-passenger turboprop planes, Air Rarotonga connects the main island with most of those in the southern group and several in the northern. You can also get between the islands by private yacht or passenger freighter. Getting to the outer islands can be a challenge, as ships make it out there infrequently and there are no firm schedules. The airport on Rarotonga is on the north- western coast, just a few kilometres west of Avarua.