If in a canoe on a river, pull out of the river during a lightning storm and try to find cover. Stay away from a metal canoe as it might attract lightning. If it is a small river, be sure not to float in a flash flood. While floating a river, one will notice the mounds of logs and other debris deposited high above normal water level by floods. Also be aware of fallen logs, sharp bends, and rocks that create unusual currents.
Currents can be strong and drown even the best swimmer.
If unsure of the conditions or your swimming ability, make sure to wear a personal floatation device. Alcohol can affect your ability to handle a canoe and swimming ability and so it is best to pick a relatively slow river if drinking and floating. Also be aware of water depth and debris when jumping into water. If fishing, be careful with hooks. Lures caught in trees or rocks can come loose when yanked and fly at high speeds.