Travel Among the Islands
It's possible to take some flights directly from the mainland to islands other than Oahu, including Maui, Hawaii, and Kauai. Those flights might not always be the most convenient for some itineraries.
If that's true in your case, don't worry. Most people traveling among the various islands take short flights on jets or other commuter planes. Both Hawaiian Airlines and Aloha Airlines operate an impressive schedule of flights all day long to most Hawaiian airports. Many of these are direct, and others connect by way of Honolulu. Passengers from the mainland commonly arrive in Honolulu, transfer to the interisland terminal, and away they go. If you miss one flight to your destination, it's likely that another will be departing soon!
Additionally, Aloha Airlines offers a seven-day “Island Pass,” which allows unlimited travel for seven consecutive days. It can be a real bargain for those travelers who really want to get around and see several islands in a short period of time.
Apart from Aloha and Hawaiian, there are also some smaller companies that can get you where you want to go. Island Air is a subsidiary of Aloha Airlines. Island travels to some of the smaller airports, such as the Lanai City airport on Lanai. Pacific Wings is another small carrier that will take you to many island destinations.
You may prefer to travel by ferry. The Moloka'i to Maui Ferry provides transportation between those two islands.
The Expeditions Ferry operates between Lahaina, Maui, and the island of Lanai.