I agree the Kukookunuku Party Bus is a must. The Jolly Pirates snorkel boat gets a little crazier than some of the others.
Take the jeep and just go tour the island on your own. You may get lost but that is half the fun!!
definatley taking that bus. the joplly was pretty mellow last year when we went. i liked the swing but my shoulder sure didn't ..lol. we had the jeep last year and man did we get lost. had a crappy map. but we found the pool and our way back and we all had a good time. got a borch map here now so we are good to go.