Me and some buddies are going fishing and will be outside all weekend, and it's supposed to pour. We had this idea of a large shelter that seemed like it would work pretty well. Take some 10 foot PVC pipe sections with male/female ends and put 3 of them together. Bend this into an arc and put each end onto some 2 foot sections of rebar we would pound into the ground. Do this 3-4 times to form semi circular ribs. Use rope to form a basic spine to keep the ribs from moving. Then just toss a big tarp over it. What do you think? I think some duct tape on the pvc junctions would help to keep them from coming undone because there's going to be a good amount of stress on them.