I might be WAY LATE with this. I'm a fairly new hanger and recently a group of us went to the beach. We went onto the sand with two SUV's and I had my ENO doublenests and slap straps (don't hate on me over slap straps...don't I have a year to convert?? ), but, of course no trees.
The attached file is how we configured for some "hang time" for a break while fishing.
It worked fine. I'm a "big boy" (250lbs. +) and everything was just fine.
...since a picture is worth 1,000 words, check it out. BUT, keep in mind that I ALREADY KNOW my drawing skills leave plenty to be desired...