GEAR GUIDE: Bivy Sacks

Gear Guide Criteria: The bivy sacks in this gear guide are characterized primarily by their stormproofness. A stormproof bivy sack is one that includes waterproof fabrics, sealed seams, and stormproof closures (e.g., storm flaps and/or waterproof zippers). A stormproof bivy can be used as a standalone shelter in inclement weather. A bivy that doesn't meet these requirements of stormproofness is better suited for drier weather, or when used with a supplementary overhead shelter (e.g., tarp, tent, snowcave).

Distinguishing bivy sacks based on their structure (hoops, poles, etc.) is a futile exercise given that many solo "bivy-style" tents are now approaching the weight of bivy sacks that feature some structure to them. Consequently, some subjective judgment has been used in this gear guide to exclude "bivy tents" from "bivy sacks" based on the use of stakes, guylines, and/or poles in bivy tents that are used to erect a structure that keeps the entire upper fabric off of your sleeping bag while inside the tent.

The criteria for the inclusion of bivy sacks in this gear guide is that they must weigh less than two pounds and not qualify as a bivy tent based on the loose definition of the previous paragraph. If you are carrying a bivy sack that weighs more than two pounds, then perhaps you should consider counseling, because the days where one needs a two pound bivy sack have long since faded away.

Also excluded from this Gear Guide are so-called bug bivies (made with full mesh uppers) and "emergency bivy sacks", which are non-breathable and (often) poorly-durable bags made with reflective fabrics designed for emergency, rather than sustainable shelter.