(this info last updated January 2013)
The channels between all the Hawaiian islands, including Oahu and Kauai, are too wide, too rough, and too windy for all but the biggest boats to make it.
There was going to be a ferry from Oahu to Kauai and Maui and the Big Island and back, but it was run out of Hawaii because of environmental concerns. Read more about that here
The airport on Oahu is in Honolulu and the Airport on Kauai is in Lihue, so again, your only option is to fly into Lihue. There are no boats or ferrys from anywhere, unless you are going to take a cruise.
In order to get to any other major Kauai cities, like Poipu, Koloa, Princeville, Wailua, or Kapaa, you’ll have to fly into Lihue and then drive.
There are cruises that go around the islands. They generally leave Oahu and then go to Hilo, Kona, Maui, Kauai, and then back to Oahu over the course of 7 days, but this is not an option if you want to stay in Kauai. You can’t take the cruise for only one or a few legs of the trip. You have to do the whole thing. I asked.:)
So, many people who want to get to Kauai want to go for a whole leg of their trip, OR are flying into Oahu but want to spend all of their vacation on Kauai.
What if you want to vacation on Oahu, but just fly over to Kauai for the day to just see what it’s like and spend the day there, and then fly right back?
You want to take a DAY TRIP. This is easy to do. You can plan it yourself – meaning you will book your own airline tickets and rent a car yourself and then drive around and do what you want to do.
Planning it your will generally be less expensive but will require you to be a more savvy traveler.
Or, you can take a pre-planned day trip or tour. Here’s some options.
So that’s it – if you have any thing to add or ask, leave me a comment! I’d love to hear your experiences! Aloha, Lisa!