This past Monday, we visited The Hidden Falls, which consisted of a 2 mile kayak trip, followed by a 2 mile hike, a lunch. After lunch, we returned the same way we arrived (hike, kayak).
We knew immediately that we would enjoy the trip when we were introduced to our tour guide, Daniel. The tour started at 8:45am, and was a great way to start the day. We were back to our cars by about 1:30 or 1:45pm.
Daniel was very entertaining and educational, whether it related to the use of the kayaks, the trip we were taking, the vegetation, as well as the native Polynesians who used to live on the land we were hiking. It was a wonderful adventure, and he called us an "adventurous" group.
The 'hidden falls' was less than spectacular. If your goal with the tour is to see the best waterfall in Kauai, you'll be disappointed, as there are better waterfalls. If your goal is to have an active day touring the island, and seeing a decent waterfall, this is the tour for you.
I'd recommend this trip for couples as well as families with teens. It would, however, be hard and overly challenging if there wouldn't be 2 able bodied people able to paddle the kayak. The wind along the river on the return trip made for a more challenging kayak trip than the trip away from the ocean.
I'm sure all the tour guides are great, but we couldn't have asked for a better guide than the 8:45 tour guide, Daniel.