A bivy sack is a simple one-man waterproof shelter. As the name implies, it’s basically a sack that you slide your sleeping bag into and is designed to keep you and your bag out of the elements while you’re sleeping. Bivys were originally used as a minimalist shelter by thru-hikers and climbers on multi-day trips.

Do you need a sleeping bag with a bivy?

A bivvy bag is basically a waterproof cover for your sleeping bag. It allows you to go camping without a tent. They have some big advantages over wild camping with a tent…. If you have a dry sunny night ahead of you, you actually don’t need a bivvy bag at all.

What is the purpose of a bivy sack?

First, what is a bivy sack? Bivy sacks are single-person, minimalist shelters that offer an additional layer of protection against the environment for you and your sleeping bag—think cowboy camping with a full-body shell.