I just got my Edge tarp today, and haven't had a chance to take it outside, but it seems great for one hammock. Two, however, I think will be pushing it if it's a solid rainstorm plus any wind. There is always the Walmart cheapo tarp! Not the prettiest, but it keeps ya dry without breaking the bank!
"Get busy living, or get busy dying."
Warbonnet Blackbird 1.0 DL
Warbonnet Edge Tarp
North Face Cat's Meow 20°
Custom HammockGear.com Phoenix Underquilt