It's about five hours, from getting in van to getting back. They shuttled us over to the launch (great group!) had lunch and had some fruit available. It's not a pleasure cruise. It's about 4 miles of paddling (round trip, with decent exertion. Up-river there (no current) down river home (but into the face of a decent wind.) You will work. The hike is more like a 1.25 miles one-way, with a river crossing. You will get thigh-deep wet. The waterfall is excellent, had a chance to swim (we had good weather, a day or two after a few days of rain.) We had an excellent guide (Alan). Highly recommend. We've been to the island 4 times, had never done this, and we're so glad we did.