We booked this kayaking trip through our resort activity desk. It was a great trip - beautiful. We kayaked about 1 hour up the Wailua River, docked our kayaks, and hiked 1 mile back to a very large waterfall - Secret Falls! It was absolutely beautiful. I do want to warn you, though, that the hike is hard, with lots of roots, creeks, and rocks to climb over. It is definitely worth the hike once you make it to the falls. The kayaking company provides lunch, included in the cost of the trip. Lunch included turkey or vegetarian sandwiches, chips, Oreo cookies, and Coca-Cola. We were able to spend about 1 hour at the falls eating lunch and swimming under the falls. We then hiked back to our kayaks and paddled back down the Wailua River.
The Wailua River is the river on Kauai where the fresh water meets the ocean. This is a guided tour, but the guide leaves you alone unless you want his/her help. I would highly recommend this trip. It is a great family adventure.