I am working on a free-standing hammock setup and a crucial part will be some high performance, light weight ground anchors. So I have decided to design my own.
But before I can determine the design criteria, I need to establish what current designs can hold and how they fail.
So this weekend I tested a few variations and here is my data. Anyone with anything to add, please help the cause.

Note: My test bed is a patch of loose to moderately packed sand. I live in Florida so this is what I deal with mostly and seems to make a good worst case situation.

1.
Description: Standard 9" Coleman aluminum tent stake, 0.5" wide "X" shape
Testing Setup: Drove the stake to full depth at approx. 30 degrees to the vertical. Line was attached at the top as standard and pulled at approx. 90 degrees to the stake.
Results: Max pullout 18 lbs, pulled through the ground at the top as expected

2.
Description: Standard 9" Coleman aluminum tent stake with additional attachment hole at 2.25" from the bottom, 0.5" wide "X" shape
Testing Setup: Drove the stake to full depth at approx. 30 degrees to the vertical. Line was attached at the bottom attachment point and pulled at approx. 90 degrees to the stake.
Results: Max pullout 12 lbs, the line began to cut through the ground however it stopped moving through the ground and pulled the stake nearly straight out of the ground.

3.
Description: Coleman aluminum tent stake cut down to 5.25" in length with additional attachment hole at 2.25" from the bottom, additional attachment hole was placed at the top of the stake for a retrieval line
Testing Setup: Drove the anchor with 0.5" pipe to approx. 18" deep at approx. 20 degrees to the vertical. Line was attached at the middle attachment point and pulled at approx. 30 degrees to the stake.
Results: Max pullout 20 lbs, the anchor clearly "set" however it seemed to turn fully around and begin to point upwards when it was pulled from the ground. I suspect that this is because the attachment point was directy on the stake and not offset as to provide a torque for setting and a "T" shape while holding.

4.
Description: 0.5" diameter PVC cut to 4.25" in length with 0.5" eye bolt at middle
Testing Setup: Drove the anchor with long screw driver to approx. 16" deep at approx. 20 degrees to the vertical. Line was attached at the middle attachment point and pulled at approx. 30 degrees to the stake.
Results: Max pullout 43 lbs, the anchor clearly "set", the failure mode was simply pulling up through the sand.