Left hand down or Right hand down?

great question! It has to do with how the water is moving in a given drop. In the photo of my friend, most of the current is going toward the rock to his left so he gets more purchase with his paddle in the water on his right side. The drop I went off of, the water is moving from left to right and I go off the left side of the ledge so there is more water for paddle purchase on my left. When a stroke is placed like that right at the edge of a drop and the paddle is perfectly vertical, it’s called a ‘boof’ stroke. It gives you extra momentum as you go off the drop so that you fly forward rather than just floating slowly off the edge. 
Thanks Megan for the great info.

Boof this…..