Ultralight bivy sacks are utilized by backpackers for cowboy tenting or below floorless shelters, reminiscent of tarps or pyramids, to guard their sleeping luggage/quilts and sleeping pads from wind, bugs, mice, and different creepy crawlers. Most are usually not waterproof and performance extra like sleeping bag covers encapsulating a sleeping pad and sleeping bag or quilt, with mosquito netting over the top and face for insect safety. They’re very completely different from heavier-duty waterproof bivy sacks used for winter tenting or mountaineering, just like the Outdoor Research Alpine Ascent Bivy, or the Rab Ridge Raider Bivy, which resemble mini-tents with collapsible rods to make them extra livable in harsh climate.
Most ultralight bivy sacks are sized to be used with a sleeping pad and a sleeping bag or quilt. But sleeping in them actually isn’t as claustrophobic as it’d look. There’s nonetheless loads of room to sleep in your aspect or prop your head up in your arm to learn at evening. Bivies with aspect zipper entry are additionally rather a lot simpler to get into and out of than ones with entrance openings the place you might want to slide in toes first. This is especially true at evening whenever you’re feeling particularly silly and uncoordinated.
Many ultralight bivy sacks have a wire loop you could tie to the underside of your shelter to carry the bug netting up off of your face whenever you sleep. You also can tie this wire to the rafters in a path shelter and use your bivy to guard you from bugs and mice. Your bivy sack additionally offers a wee bit extra privateness inside a shelter if you wish to turn into your lengthy underwear.
When sleeping below a flat tarp or catenary reduce tarp, a bivy sack helps shield your sleep system from splash-back, which happens when rain bounces off the bottom and below your tarp and in your sleeping gear. This may be a problem when you’ve got a slim rectangular or catenary reduce tarp however is much less of a priority if you happen to use a wider one, whose sides are staked near the bottom in unhealthy climate.
Most ultralight bivy sacks don’t impart a lot further heat to your sleeping bag or quilt at evening, perhaps 5 levels tops, though they are going to block a breeze from chilling you. They are sometimes made with a prime cloth that’s fairly breathable to assist vent any condensation build-up at evening. In extremely popular climate, you should use the highest cloth of a bivy like a sheet for sleeping. Some ultralight bivy sacks can be found which might be all mesh to be used in hotter climate use, however the norm is an element mesh and half stable cloth.
Ultralight bivy sacks are fairly delicate items of substances made by hand and should be handled gently if you need them to final. If you purchase a bivy sack that has a zipper, it’s good to lubricate it periodically with Gear-Aid Zipper Lubricant so it doesn’t snag, and to dry your bivy sack out after each journey you’re taking to keep away from mildew. If you see black mildew spots start to type on the bivy cloth, washing your bivy sack out with Revivex Odor Eliminator will get rid of the mould and forestall injury to the material.
Recommended UL Bivy Sacks
Why Would You Use an Ultralight Bivy Sack?
So far we’ve mentioned what an ultralight bivy sack is, however not why you’d need to use one. There are principally two causes: tarp tenting (for gear weight discount) and wilderness immersion.
Tarp tenting with a flat tarp, a catenary reduce tarp, or a pyramid tarp is lighter weight than utilizing a tent, even an ultralight Dyneema DCF tent from the likes of Zpacks or Tarptent. You nonetheless want some form of insect safety below a tarp and at 5-8 oz, a bivy sack weighs considerably lower than an internal tent or internet tent, making it attainable to hold an entire shelter system that weighs below a pound.
In addition, sleeping in an ultralight bivy sack is a way more immersive solution to expertise the wilderness than sleeping inside a tent, with partitions and a ground. If you cowboy camp in a bivy sack or sleep below a tarp, you’ll really feel a lot nearer to the surroundings surrounding you.
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