A Bivvy bag or bivouac sack is a just a waterproof sleeping bag cover. They are mainly used by the military as a light weight, low bulk sleep solution but also by hikers, campers and climbers.
They are a personal – one man shelter and can be used in situations where a tent can’t be used.
A Bivvy bag can replace the need of a tent in many situations as it fulfils the role of a tent to shelter from wind and rain. When combined with a sleeping bag and sleeping mat, a Bivvy bag creates a complete outdoor sleep system.
Why are they useful?
They are a useful piece of kit as they offer a light weight shelter solution that is waterproof for adventures in camping, hiking and bushcraft. They can be compacted down into a minimal space in your pack for those where carrying capacity is at a premium or are travelling light. One benefit of using a Bivvy bag with your other sleeping gear is that it creates and additional thermal layer increasing the temperature range of your sleeping bag.
What types and styles and materials are there?
Bivvy Bags come in many different styles and materials dependant on intended use. Many are made from waterproof and breathable modern fabrics such as GorTex or laminated Polyester. They come in a variety of colours and even camouflage patterns if you want to blend into ground cover. Hikers and climbers may choose bright colours for use in an emergency situation where they need to be seen!
What are the advantages?
Light weight, Waterproof, Durable, Low bulk, Versatile, Dependable, Additional thermal layer, Simple solution.
What are the disadvantages?
Not suitable in extreme conditions on it’s own! Condensation can sometimes accumulate on the inside – although modern breathable fabrics counter this!
Bivvy Bags compare to other forms of man-made shelter such as tents. Tents are heavier and bulkier items and are generally more expensive.
Why get a Bivvy bag?
A Bivvy bag can be an excellent item of kit if you are travelling or sheltering in situations where you need something to protect you from the weather, but have weight, or bulk restraints. They are good if you are prepping a bug out bag or similar emergency shelter solution. The single person, low profile and foodprint of the Bivvy bag means you can shelter in small or secluded spaces where you couldn’t pitch a tent. The ability to shelter in unlikely places means that you can also use a bivvy in an escape or evade situation.