Kids will have a blast! A lot of time will be spent with them playing in the water, therefore set them up with comfortable PFDs, snorkeling equipment, water toys, especially rent one of the large 'lily pads' for them to play on behind the boat. Perhaps plan to have more meals on the boat, they will not appreciate the slow service at some restaurants. Take DVDs and something to play DVDs, or download movies on iPad. They will like the trail through the Baths. I like Kelly's Cove mooring balls, because of shallow water where they can see the bottom. Also, the Caves and the Indians are good day spots.