Waimea canyon trip = 5 stars, highly recommended. River trip worth seeing but probably only a 3. Guide Clarence was very pleasant.
Waumea Canyon was something to see. Not as big as the Grand Canyon, but beautiful. The river boat ride was ok, not as interesting as the other tours.
Waimea Canyon is definitely worth seeing, our tour bus driver "Nani" was fabulous and provided an extremely informative commentary. Tour also included stop at lookout to get pics of waterfall and river. Entertainment on river cruise was fun, although we were not that impressed with Fern Grotto.