The front pieces aren't sails. They're not fins either.
They're extensions necessary to reach the sides of the creek. Tomorrow we'll put on the pins for the stones on, disassemble everything, put it in Don's trailer, and after he helps me finish the barn project. He can go home. /forums/images/graemlins/grin.gif
Here's what you'd see if you were a pebble involved in bridging one oh one at Don's creek Texas.