Lahaina go to kalalpali beach. get the bus for $2 dollars behind the abc store in town, honolulu you can do everything yourselves, in kauai we did the zipline excursion which was great, worth the money, in hilo there is nothing near the port so i would choose a trip, there is no beach nearby or anything, windward coast and waterfalls is a nice one. it will be warm once you grt to the islands, but in feb your journey down and back will be freezing, so take warm clothes, sweatshirts tracksuits etc, you will need them enjoy.
It is better, cheaper, and more interesting to go it alone on shore excursions. If you google 'ports of call' and look at the 6/7 answer you will find a lot of informatio.