Sleeping in a tent and sleeping bag isn’t always everyone preferred method for a night in the wilderness. To most, the comforts of having walls to protect from elements, insects and whatever else lurks in the night helps us sleep at night, but for others all this isis unnecessary added weight!
So what is a bivy sack? Well bivy is actually short for bivouac and originated as a quick, lightweight shelter for hikers and climbers who needed emergency place of refuge from the elements on multiday trips....Read More
They pretty much have two purposes, one being to keep your sleeping bag dry, and two being to increase your warming capacity by about 1 degrees. While original bivy sacks were mostly just a sleeping bag cover that shielded the user and their bag from the rain, bivy sacks have much since evolved. You can still find ultralitebivy’s that serve this purpose, but options have now expanded to include much more substantial bivy’s as well as bivy shelters.
The Evolution of Bivy Sacks - Over time, the look and features of bivy sacks have changed. Most bivy’s are constructed of 2 tiers. The bottoms are generally made of a bit more durable material (usually a high grade nylon) that is coated in urethane. This makes it durable, so you can virtually set up anywhere, and waterproof when the weather takes a turn for the worst. The top tier is usually made of a ripstop nylon that is treated with waterproof and breathable elements.
Bivy shelters tend to resemble that of a small tent. For only a lbs or two more and still significantly lighter than carrying along a tent and sleeping bag, bivy shelters carry a bit more of the luxuries that your traditional tent can provide. Additional headroom, and a full enclosure which allows you to totally block out the elements and bugs are the main reason to go this route. These tend to be popular with hikers looking for the utmost in weight reduction and other non-climbers.
Are Bivy Sacks for me? - For the average hiker or camper bivy sacks are probably not necessary equipment. While bivy sacks reduce weight and packable size drastically, for most recreational folks they just aren’t practical, and take away a lot of the benefits that most have grown accustomed to. It’s important to keep in mind that the average bivy doesn’t give you a whole lot of room to move around in. If you’re uncomfortable in tight places, or a bit claustrophobic then a bivy probably isn’t the best option. It also just might not be 100% necessary. While a bivy is great avid climber during a week’s long summit, it’s probably not really conducive and is probably more of a hinderance on your recreational weekend river trip. Are there other lightweight options? Sure, hikers or campers who want a lightweight option can just step up to aultralight one persontent. There are still plenty of 1-2 lb options out there that provide much more livable space than a bivy and will probably keep you a bit more comfortable. For your super minimalists and mountaineers however, a bivy is just another way to shed those unwanted pounds.