The jetboat ride on the Lachine Rapids sounds fun - count me it!

Way Omni: the son of the inventor of the jet boat decided back in 1960 to try going upstream through the Grand Canyon. Lava Falls (rating varies between 8 and 10 on the 10-point scale that's unique to the Canyon) provided the most difficulty - it took something like 45 attempts (over a couple of days, I think). After that, the rest of the Canyon was a piece of cake.

The Park Service immediately added a regulation prohibiting upstream runs!