Experience up-river white water rafting as you ride the force of the highest tides in the world! As the contour of the river narrows, the sheer volume of water has nowhere to go but up. The tide is travelling 30 miles inland, quickly reversing the natural flow of the river — so when the tide’s running high, Shubie’s tidal rapids can stir up 16-foot waves! In the course of your rafting adventure the river level will rise 20 to 30 feet.