>>230058These are also very easy to DIY, and many good gear companies make them, but if you want to see how it’s done, Google the Titanium Goat bivy (pic related).
It’s gotten to the point where the DWR bivy is obligatory gear for tarp-campers wanting to get a little extra weatherproofness out of their set-ups. The bivy protects their sleeping bag from blown rain and morning dew, and reduces drafts, thus adding a few degrees of warmth. Some companies, like Montbell, even make waterproof sleeping bag covers (pic related) that make no pretense at being a stand-alone shelter.
Take the same concept still a step further, make the top entirely out of bug netting, and you have a tarp-camper’s solution to bugs.
I have looked at bivies from every angle and I’ve only found four real niches: temporary shelters for mountaineering, primary shelters for desert camping (DWR bivies) and for stealth camping (waterproof bivies), and use in conjunction with tarps to bolster weatherproofness or bugproofness of the shelter system.
