I took Rainbow Kayak Tours afternoon (12:30 PM) Kayak tour up the Waimea River to secret falls. This was a great tour and I was lucky enough to have Matt for my guide. He was very friendly and knowledgeable about Kauai. He was especially knowledgeable about the foliage on the island. I felt that Matt gave us good direction and good information throughout the tour. The Waimea river is rather calm (at least on the day of my tour, June 10) and so kayaking was very easy. I was in a solo Kayak and was a bit nervous that I would trail the rest of the group, but I actually somehow took the lead. The hike to secret falls is not too strenuous and mostly flat, so that would be pretty easy for most people too. Do bring water shoes as you will need to walk through a lot of water. In short, I highly recommend this tour and recommend Matt as your guide if you can get him.