If you know any one that works in a paper mill have em get you dryer canvas that has been removed from the machine. It is a synthetic type fiber, very strong and water pours through it. If you tamp the sand/gravel, screed it flat, lay the dryer canvas down. I know for a fact you can use your creeper and move a tool box around. Only problem is finding a source. The take offs are ussually free for the asking, and widths range from 10'-30'. A piece 24x24 is about all one person can handle.