We spent the day with David on our Grand Island tour... visited black beaches with turtles, the volcanoes, Hilo, two waterfalls... rainforest... All in one day. Our Guide David was outstanding... his commentary/information was fun and informative. In particular, he recommended we take the rain gear to one of the waterfalls, even though it wasn't raining... YET. We had coats and most everyone else was getting soaked! That type of experienced tour guide is invaluable. Highly recommend. It is a long day, not for little kids.