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Join Date: Sep 2002
Location: LAX/TPE
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Posts: 46,996
2 days on the Big Island is way too short - you need at least 3 to 4 full days (exclusive of arrival, departure) to see even just the highlights.
Here is what I would do...
Day 0 - travel to Hawai'i, arrive Lihue
Day 1, 2 & 3 - Lihue (Kaua'i)
Day 4 ,5 and 6 - Waikoloa Village (The Big Island)
Day 7 & 8 - Kahului (Maui) - Option 1
Day 7 & 8 - Honolulu/Waikiki (Oahu) - Option 2
Day 8 evening - departure home
Whether you choose Option 1 or 2 depends on how badly you want to visit Honolulu and see the sights on O'ahu or what type of vacation/activity experience you're seeking.