Low Head Dams
A low head dam is a drop in the river that creates a hole that is perfectly uniformed the whole way across. It has a steep angle of entry, no shoulders to escape from, and no imperfections to exploit for an exit. Take a look at one some time and look at how far downstream the boil line is. They can often be quiet and difficult to spot from water level upstream. They are primarily man made but natural ones do also occur. They can hold boats and will in many cases hold swimmers too. They are not safe to play in.
Stay away from low head dams. Don’t attempt to run them, if you can’t safely paddle around them get out of your boat and walk around.
Use local river guides forums and guidebooks to find out if there are any low head dames on the section of river you plan to paddle.
Stay safe out there guys and girls.