If you are thinking of sleeping in a bivy sack then it will be handy to know what it is and how it is actually used. A bivy bag or sack is essentially a single layer fabric bag that can be slept in. The short form of ‘bivouac‘, a bivy can also be a temporary shelter, like in caves, under trees, under large overhanging rocks or anything else that can be found.
Who Uses A Bivy Sack
A bivy sack can be used by anybody spending nights outdoors. Climbers, hikers and the likes make use of them to keep their backpacks lightweight. For example, in mountaineering, bivy sacks are carried even when mountaineers don’t expect an overnight stay.
They serve as backup emergency options should anything happen that would mean they become stuck in a place. People embarking on solo adventures may also consider a bivy bag as a compact and more lightweight option instead of a one-person tent.
How to Use a Bivy Sack
Setting It Up: Just as it is with setting up tents, the same rules apply here. Select an area that won’t be flooded if it rains, not in the path of animals or humans (e.g. an animal trail), is free of sharp objects and is safe enough to sleep in for the night (out of avalanche zones in the snow, away from any fire pits, etc).
Ideally, you’d want a flat spot.
This is quite easier to locate than finding a place to pitch a tent due to the fact that you’d be looking for a significantly smaller space. Bivy bags can slide on sleeping mats, so it’s better to choose a flat spot.
Sleeping Mat: A handful of models have straps to keep your sleeping mat in place. Making use of a sleeping mat is advised since you’ll lose a lot of heat through the ground. These straps will help in keeping the mat in place as you toss and turn.
Turning in your Sleep: With the absence of a sleeping mat, it’s basically as if you’re inside a tent. If your bivy doesn’t come with straps, you can choose to install some by making use of flat elastic straps and glueing velcro material on the middle ends so as to be able to adjust it. After this, glue each end to the bivy base.
Pack Contents: After setting up your bivy, there will surely be items that are leftover. Depending on the space you have left, you can decide to stuff the rest items around you in the sack, or leave them inside your bag – while using your rain cover to protect it.
However, this will not be efficient in heavy rain, so you can decide to get a large pack liner instead. Remember to take food with you inside the bag.
Dealing with Moisture: Normally, you’d want to use the mesh instead of the headcover – except for when it snows or rains. This will allow for the best ventilation possible. If it actually rains and you need to cover up, ensure you leave a little opening even though your bivy bag may have been made with Gore-Tex fabric or a similar “breathable” fabric.
You should know that in practice, it actually doesn’t breathe as well as you think. Ensure that you don’t sleep in any wet clothes and also avoid breathing into your bivy or sleeping quilt. Setting up camp under low hanging branches means lesser condensation and a warm night’s sleep.
This is as a result of the reduction in radiant heat loss. The only disadvantage of this is that the views from these types of locations aren’t as good as other spots.
Sleeping in the Snow: When sleeping in the snow, ensure that you choose a safe space for the night – not avalanche paths or under trees loaded with snow.
You may find that the condensation freezes over during the night and it will lead to the Gore-Tex fabric being less breathable.
Additional Improvements: Including sleeping bag straps to your bag (if they were not present before) will make sleeping easier – especially if you’re someone who tends to toss and turn a lot. For bivy sacks that don’t have hooped tent poles for keeping the headcover off your face, you can decide to use some steel wire to address this issue by making it into a tripod shape.
This will have almost the same weight as a hooped tent pole. Remember to bend the ends of the wire back onto themselves. This will stop it from poking through the bivy sack. If you’re expecting rain, a small tarp – even for the head alone – can be a great addition.
This might add weight to your total setup, but by making use of small tarps (or even a poncho), you can still keep it well under a one-person tent. Making use of a water-resistant sleeping bag is advisable as the problem of condensation will become less of an issue. Most high quality and modern sleeping bags are manufactured using this type of materials.
What is it like to Sleep in a Bivy Sack?
This is normally the very first question people who haven’t used one before asking bivy users. So, what is it like to sleep in a bivy sack? Here, we’ll try to paint that picture.
Sleeping in your bivy with the head panel open or just making use of only the mesh is the best way to use your bivy bag when conditions are clear. Even when the weather changes and rain starts to fall, it is always advisable to keep a small hand length portion of the bag unzipped. Water will not normally splash into the bag.
A hooped tent pole will keep the headcover and mesh off of your face and in my opinion, is a must-have. A lot of people find it quite uncomfortable without one.
For extra gear that is floating around, you can decide to take as much as you can inside the bivy. This might include food and even rubbish. Put the rest into your backpack and place this backpack into an oversized pack liner to ensure it is waterproof.