Bivy Sacks Beckley WV
Mt. Hope, WV
Mount Hope, WV
Mount Hope, WV
Lightweight shelters for the adventurous spirit
A bivy sack is the short term for bivouac sack, which is basically a small, lightweight and compact personal shelter that's used as a survival/emergency bag for things such as day hikes, summit attempts, cross-country skiing, snowmobiling, and more. It's more or less a combination of a tent and sleeping bag that's made from tough, waterproof, windproof fabrics that will hold up to abuse, and provide you with a warm shelter. A good bivy sack should come with a foot vent and a large opening to keep you comfortable and dry on the hottest nights.
Bivy sacks are often used by people such as mountaineers, cyclists and kayakers who like to travel fast and light, and who would rather battle the elements in a personal shelter than have to carry and setup a bulky, heavy tent. The bivy sack was originally invented for climbers who preferred lightweight emergency shelter for their sleeping bags during multiple-day climbs.
The first versions of bivy sacks were basically just waterproof nylon slipcovers for sleeping bags. They kept the person and the sleeping bag dry, but they didn't have system for ventilating body heat, which often meant they were uncomfortable. These days most bivy sacks have full length zippers for ventilation, and some people even sleep in a bivy sack without a sleeping bag. A good bivy sack should also offer you breathability, easy set-up, and a small footprint that lets you setup camp just about anywhere you can lie down.
Modern bivy sacks are usually made with 2 tiers of material. The bottom tier is generally built with a durable grade of nylon such as taffeta, which is then coated with urethane to make it waterproof. This is basically the same fabric that most tent floors are made of.
The top tier of the sack is usually made with a lighter material such as ripstop nylon, and treated with one or more layers of a waterproof/breathable substance.
A bivy sack isn't entirely foolproof, and rain can sometimes invade the sack through the unshielded head opening. However, you can pull the drawstring of the head hole tight to minimize water penetration. Some bivy sacks let you make armholes in them, which allows you to basically wear them and perform your camping duties while you're still protected and warm. Condensation can also form in a bivy sack as moisture can collect on the inside of the treated material. Because of these examples, bivy sacks are usually best for trave...