The Superferry is a high-speed catamaran ferry designed to carry passengers and vehicles between the Hawaiian Islands. Currently (as of October 2008) the Hawaii Superferry is operating between the Islands of Oahu and Maui and is expected to start service to Big Island (Hawaii) in May of 2009. The ferry makes two 3 hour round-trips to Maui four days a week and one round-trip 3 days a week.  It departs Honolulu at 6:30am and returns at 2 pm.  The second voyage departs Honolulu at 3:30PM and returns at 11PM. 

If you bring your car, the ferry is especially easy because you can load up your car and simply drive onto the ferry in Maui and drive off in Honolulu (or vice versa) without any parking charges or airline baggage fees.  Plus you get to see the beautiful islands from the ocean which is pretty cool.

Though an easier and cheaper way to travel than flying and renting a car the ferry has some flaws.  The travel times are longer than flying interisland, even when airline check-in and security clearance times are factored in.  Also some passenger report seasickness so be sure to take Dramamine before you go on board if you are prone.  Ferry service can be cancelled with 24 hours notice if very rough seas are present - thus and can occasionally force travelers to make other arrangements.

Unlike airfares that change every day, prices are fairly stable except for fuel surcharges because they are regulated by the PUC.  At the time of this writing (October 2008), the fares are $49 per person plus $65 per vehicle each way.  Even if you do not bring your car, it will be typically cheaper to take the ferry between islands and rent a vehicle than to fly especially with the new airline baggage fees. 

The service was designed for Hawaii residents but tourist use is growing because although visitors usually come for only 7-10 days, they often want to see the beauty of other islands.