How could we use an umbrella with a bivy for more complete protection?
It seems some bivies would be waterproof except for their closure system at the top. An umbrella could augment this nicely. What bivies would work best for this? We're looking for fully waterproof sacks that aren't stormproof due to their head end sealing system.
Possibly some fabric (waterproof) that attached to the umbrella would be able to create an enclosed space for a bivy.
Currently i often pitch on end of my plain plastic tarp low and keep the other quite high. At night I use the umbrella as a door; this works rather well says I.

