Capt.Albatross (1301561) writes "The flat surface of the Racetrack Playa in Death Valley is littered with rocks, some weighing hundreds of kilograms, each at the end of a track indicating that it has somehow slid across the surface. The mechanism behind this has been the subject of much speculation but little evidence, until a trio of scientists caught them in action with cameras and GPS."
I've never been canoeing before, but I imagine there must be just a few
simple heuristics you have to remember...
Yes, don't fall out, and don't hit rocks.