Last Updated on May 11, 2021
People who enjoy outdoor pursuits need a range of equipment. This includes some form of shelter for when they spend the night outdoors. While a tent is the most commonly used gear for overnight shelter, this is not the only option. An alternative to a tent is a bivy sack and these are particularly popular amongst enthusiasts of ultralight backpacking, hiking, mountaineering, and climbing. Some people also use an emergency bivy bag when they need protection from the elements fast. Here is a guide to buying the best bivy sacks and reviews of the best options available now.
Quick Overview of the Best Bivy Sacks
Regular Bivy Sack
|Outdoor Research Alpine Bivy||1.4 lbs||Outdoor Research||Check Price|
|Rab Alpine Bivy||1.5 lbs||RAB||Check Price|
|Black Diamond Big Wall Hooped||1.14 lbs||Black Diamond||Check Price|
|MSR AC Bivy Sleeping Sack||0.94 lbs||MSR||Check Price|
|Tennier Camo GTX GORETEX Bivy Sack||1.8 lbs||Tennier||Check Price|
|Outdoor Research Advanced Bivy||2.35 lbs||Outdoor Research||Check Price|
Emergency/Survival Bivy Sacks
|Tact Bivvy Lightweight Bivy Sack||0.3 lbs||Survival Frog||Check Price|
|Life Bivy Emergency Sleeping Thermal Bivvy||0.26 lbs||Go Time Gear||Check Price|
|S.O.L Escape Pro Bivvy||0.5 lbs||S.O.L||Check Price|
|Mezonn Emergency Survival Bivy Sack||0.35 lbs||Mezonn||Check Price|
|Delmera Emergency Survival Sleeping Bag||0.29 lbs||Delmera||Check Price|
|2GoSystems Thermally Reflective Bivvy||0.85 lbs||2GoSystems||Check Price|
Reviews of the Best Bivy Sacks (Regular)
If you use your bivy bag regularly and are willing to spend more to get useful features, then the Outdoor Research Alpine Bivy is a good option.
This bivy sack is made from durable and good quality fabrics that are both waterproof and breathable, including no-see-um mesh for ventilation.
This waterproof bivy sack is fully seam-taped and has a hydroseal floor with an anti-fungal coating.
It comes with a dual-pole system if you want to increase the space and ventilation in your bivy sack. However, if space and weight are crucial issues, you can simply leave the poles at home and use it as a regular bivy sack.
The extra features of this bivy sack include five stake loops, sleeping pad straps, an internal mesh pocket, one guy line loop, and a high-volume toe-end.
- The option for more space
- Good protection from the elements
- Quality materials
- Suitable for extreme conditions
- Not suitable for people over six feet
The multiple features make it a great bivy for people who intend to use it regularly and not only in an emergency.
If you are looking for a lightweight bivy sack to use in various conditions, then this product is suitable for most situations and will appeal to those who enjoy a range of outdoor pursuits.
It is waterproof with sealed seams and a coated nylon bathtub floor to prevent floor moisture entering your bivy sack.
This is a relatively lightweight bivy as it weighs 18 oz. While this is a little heavier than some other bivy sacks on the market, it needs the extra weight to give a superior level of protection for extreme conditions.
This is a differential cut sleeping bag pattern design, meaning it is a good fit for the shape of most bodies.
It has a two-way zipped ventilation area that gives several options for sleeping and breathing easily. It also has a storm flap over the opening for extra protection from the elements.
- Super light
- Wide opening for sleeping options
- Two-way zipper
- Good-sized storm flap
- Hardly any condensation
- Bright color for safety
- Delicate fabric
For the serious outdoor enthusiast who spends time in extreme conditions, this is one of the best bivy sacks. The only point to note is that you should brush down your sleeping area before getting in the sack as the fabric is more delicate than most.
This Black Diamond bivy has a great design that gives ultralight backpackers more space than you would expect in a regular bivy sack. It provides all the protection from the elements you could need.
At 17.4 ounces, this is a little heavier than some of the emergency bivy sacks but is still lightweight enough for ultralight backpackers as a lighter alternative to tents and sleeping bags.
This is made from waterproof fabrics and has taped seams for extra protection from the weather.
This has greater space than most other bivy sacks thanks to the sewn in flexible wire. This means it is less restrictive and claustrophobic as you have more room to move and the fabric is not too close to your face.
- Secure anchoring
- Not compact
This is a great bivy for those who find regular bivy restrictive and claustrophobic as it has extra space inside. The price means it is best for those who are keen outdoor enthusiasts and not occasional hikers.
This mid-priced bivy bag is a sound choice for people who enjoy outdoor activities in various environments.
The bivy sack is made from a waterproof, sealed nylon fabric and the floor of the sack is coated to prevent groundwater getting to you.
This is made from a breathable fabric that provides good ventilation and reduces condensation. It also has a zippered mesh panel that provides further ventilation but stops bugs getting into the bivy bag.
It weighs only 10.1 ounces, so it is an excellent lightweight option. This is also a compact product that will take up little space in your backpack.
- Well ventilated
- Good level of water-resistance
- Zippered panels
- Good shoulder width
- No zipper on the waterproof shell
This is one of the most comfortable bivy sacks, so it is good for regular use in adverse conditions. The lack of a zipper on the waterproof shell is not too much of an issue if you are facing against the wind.
This bivy sack is part of the United States military modular sleeping system, but it works just as well alone.
This bivy sac has a good level of resistance as it is made from durable, treated fabrics. It is also windproof, which makes it ideal for sleeping in most conditions in an emergency.
The camouflage design of this bivy sack means it is good for tactical operations. However, it is also a great design for hiking, backpacking, trekking, and hunting.
Compatible with Sleeping Bags:
You can use this bivy sack as a liner or extra sheet with most other sleeping bags to increase the temperature.
It has a zipper for easy access and a storm flap for added protection from the elements.
This is a decent size and its 84-inch length makes this a good option for tall people. The shoulder width is 35-inches and the width at the feet is 23-inches.
- Good design
- Snap Storm Flap
- Zipper access
- Heavy for a bivy sack at 1.8 pounds
- Head area gets damp
This is one of the best options for taller people as it is a good length and the zipper gives easy access.
For a high-level of protection from the elements, this is one of the best bivy sacks available now.
Not only is this bivy sack made from breathable material, you can also increase the ventilation by unzipping the vent at the base of the bivy sack. It has removable no-see-um mesh to improve breathability and reduce the likelihood of condensation.
The durable GORE-TEX material protects you from the wind and offers a high level of water-resistance. The floor of the tent is hydroseal to prevent groundwater from seeping into the bivy sack and it is treated with an anti-fungal coating. Furthermore, the seams of this bivy sack are taped to prevent leakages.
Patented Dual Pole System:
You can sleep with the bivy sack touching your skin or you can create extra space and air by using the patented dual-pole system. This lifts the bivy sack away from your body, so it is good for those who feel claustrophobic when sleeping in a bivy sack. It also makes a little more room for your belongings.
- Extra space with dual-pole system
- Machine washable
- Good quality materials
- Heavy at 2.35 pounds
- Hood moves around
- Poor quality zipper
In terms of providing protection from the elements, this is a great bivy sack available and the downsides of this product are minor.
Review of the Best Emergency/Survival Bivy Sacks
This lightweight bivy bag is great for use in emergencies as a survival bivy sack and is one of the cheapest options available.
Emergency Bivvy Bag:
This is a great option as an emergency bivy bag as it is bright orange to help rescuers find you. It is also made with HeatEcho material that reflects 90 percent of your body heat back to you. This will increase your comfort in an emergency.
Ultralight Sleeping Bag:
Weighing just 4.8 ounces, this is one of the lightest bivy sacks on the market. This makes it ideal for people who enjoy ultralight backpacking, hiking, trekking, mountaineering, and climbing.
You can also use this lightweight bivy bag as a sleeping bag liner as it will increase the heat in your sleeping bag by up to 20 degrees.
Despite the thinness of the material, these are a durable,windproof, and 100 percent waterproof bivy sack. The reinforced taped seals guarantee that no water can enter the bivy sack.
- 6-month guarantee
- High water-resistance
- Easy to use
- Packs tightly
- Bright orange
- Tears easily
- Sticks to itself when unpacking
It’s so lightweight and ideally suited for ultralight backpacker, hikers, and mountaineers who want a cheap, emergency bivvy sack. It is also worth considering for using as extra warmth for winter camping expeditions.
The design of this sleeping bag means it is one of the best survival bivvy sacks you can buy and it is ideal for a variety of outdoor pursuits.
Good for Extreme Conditions:
The design of this bivvy sack is for use in extreme conditions and it is an all-in-one bivy sack, emergency blanket, and survival shelter. It will keep you warm even in freezing temperatures as it has a reflective interior that reflects 90 percent of your body heat back at you.
Designed for Emergencies:
Although you can use this bivy sack for general outdoor pursuits, its main purpose is for use in emergencies. Not only will it give you the protection you need, it is also bright orange so that you are noticeable to rescuers. Furthermore, it has a survival whistle to alert people and a patent-pending drawstring that you can use to secure your gear, make repairs, build a shelter, or start a fire.
In terms of durability, this is a great option on the market. Although the material is ultralight, it is also extra thick and puncture resistant. This means it is long-lasting and can stand up to use in extreme conditions.
Protection from the Elements:
This waterproof bivy sack is made from polyethylene material and has sealed seams. This will protect you from all the elements, including the wind and snow.
At just 4.1 ounces, this is one of the lightest bivy sacks you can buy. It is also compact as it fits neatly into a waterproof stuff sack that you can store in your backpack until you need it.
- Good in an emergency
- Bright color
- Lots of condensation when used with a sleeping bag
It is ideally suited to those who enjoy outdoor pursuits in extreme conditions and are most at risk of facing a survival situation.
This emergency bivy sack has a unique design to keep people warm and protected in a survival situation.
This survival bivy sack is bright orange so it is easily seen by rescuers in the event of an emergency. It will keep an injured person warm as it reflects 90 percent of their body heat back at them thanks to the reflective materials inside.
The materials are coated so they are 100 percent waterproof. The bivy sack has taped seams to prevent water from getting in at these points.
The tent is made from an evolutionary material that is breathable and adapts to the humidity level. This means the bivy sack has a good level of ventilation and there is little condensation.
Compact and Lightweight:
This bivy sack packs tightly into a stuff bag that is easy to store in a backpack. It is ideal for ultralight backpacking as it weighs only 8.5 ounces.
- Well ventilated
- Bright color
- Easy to set up
- A tight fit
This bivy sack is just as good for emergencies as it is as an alternative to a sleeping bag during the summer months. It will appeal to ultralight backpackers who want the option for outdoor sleeping in the summer and a backup for the winter for either an emergency or as a liner in their sleeping bag.
A handy bivy sack to keep in your backpack in case of emergencies while out participating in outdoor pursuits.
You can use this product as either a bivy sack, an emergency blanket, or a sleeping bag liner. It is suitable for almost all outdoor activities, including sailing, cycling, climbing, hiking, camping, and backpacking.
Ultra-Lightweight and Compact:
The Mezzon Emergency Sleeping Bag Survival Bivy Sack is ultra-lightweight at just 5.6 ounces. It packs away into a compact waterproof stuff bag which you can store in your backpack.
The durable materials are thicker than many other bivy sacks and this means they are reusable if you take good care of them. They are also soft for extra comfort.
- Good for an emergency
- Durable materials
- Waterproof with sealed seams
- Easy to use
- No zippers for opening options
This product is a good choice for people who enjoy a range of outdoor activities and want the reassurance of knowing they have something to protect them in the event of an emergency. However, they are not for general use as a bivy sack if you spend regular nights in extreme conditions.
This is one of the cheapest emergency bivvy bags available, so it is ideal for keeping in your backpack in case you run into trouble.
Lightweight and Compact:
At only 4.6 ounces, this is an ultra-lightweight bivy sack that packs compactly into a stuff sack and will not take up space in your backpack.
Good for Extreme Conditions:
NASA originally designed this bivvy sack for use in emergency situations and they made sure it could provide protection in all conditions. The reflective interior reflects back 90 percent of your body heat to keep you warm even in freezing conditions and the bag offers a high level of water-resistance against rain and snow.
Designed for Emergencies:
It is a bright orange bivy sack, so a victim is easily identified by rescuers. The thick, durable material keeps a victim covered and warm to reduce shock.
- Money back guarantee
- Not for regular outdoor sleeping
This bivy bag is not intended for regular use, it is simply for emergencies. The low price makes it worth buying to keep in your backpack when enjoying outdoor pursuits in case you run into an unexpected situation.
A good warm bivvy sack that you can also use as a sleeping bag liner, this product is great for many outdoor activities throughout the year.
It has a thermally reflective interior for added warmth and you can use it as a sleeping bag liner to increase the temperature.
The breathable fabric of this bivvy bag is also water-resistant. Unlike many other bivvy bags, it also offers protection from the sun.
At just 14.1 ounces, this is a good option for ultralight backpacking, hiking, and trekking.
This bivy sack has both inside and outside zippers. This makes it easier to get in and out of the bag comfortably.
As it is made from strong materials, this bivy sack is durable. It is tear-resistant which makes it good for using on a variety of terrains.
- Use as a warm sleeping bag liner
- Two zippers
- Both sun and rain protection
- Not the best for extreme conditions
The 2GoSystems Trifecta v3 Standard Thermally Reflective Bivvy is a good option for people who enjoy outdoor pursuits throughout the year. Although it is not the best choice for extreme conditions or for emergency situations, it is a great alternative to a sleeping bag in the summer months.
Things to Consider When Buying a Bivy Sack
When choosing a bivy sack, it is important to buy the right one to meet your needs. To make sure you have one of the best bivy sacks available, you should consider the following points.
A bivy sack is only a small item intended for use as a lightweight alternative to a tent as it will protect you from the elements. As it is only small, there is not a lot of room inside a bivy bag. Therefore, you should consider whether you are happy sleeping in such a tight space before buying one. If you are not happy with this situation, consider a bivy shelter as a mid-point between a bivy sack and a tent.
- There are usually two tiers of fabric in a bivy sack.
- The bottom tier is usually a durable material, such as nylon. This is often coated in urethane to improve its waterproofness.
- The top tier is a lighter fabric treated with a waterproof and breathable laminate.
- It is important that the materials used for a bivy sack are lightweight, breathable, and waterproof.
Level of Water-Resistance
The main purpose of a bivy sack is to keep you and your sleeping bag dry. Therefore, it is essential that a bivy sack is waterproof.
- Check that the outer tier is treated with a waterproof substance.
- Check that the seams are factory-sealed to improve the level of water-resistance.
- Traditionally, bivy sacs have openings for your eyes and your mouth to allow you to breathe. The downside of this is that it can allow water inside the bivy sack.
- Advances in technology to create breathable fabrics mean that many modern bivy sacks do not have holes. This cuts the chances of water entering the bivy sack.
The zippers are an important part of a bivy sack and there are different options available when it comes to this feature.
- A full-length zipper gives more ventilation options.
- Multiple zippers mean you can create armholes. This will allow you to cook or sort your gear while wearing the bivy sack.
Bivy sacs are a very basic item, so there is not a lot of difference between them in terms of extra features. One feature that some bivy sacks have is a strap. You can use this to secure your bivy sack and sleeping pad in place.
Ultralight backpackers and hikers often avoid tents as they are bulky items to carry. However, they may find a bivy sack restrictive and a little claustrophobic. Therefore, they may look for an alternative to either of these options. A bivy shelter is what many people would consider the mid-point between the two. These are a minimalist option, like bivy sacks, that will appeal to fans of the ultralight approach to outdoor activities. However, they offer a little more interior space than a bivy sack and these appeals to those who struggle with the claustrophobic conditions of a bivy sack.
Bivy Sacks vs. Tents
Purpose- Bivy sacks and tents have completely different purposes. So, while one will suit one group, the other will suit a different group. Bivy sacks are intended for outdoor enthusiasts following the ultralight ethos. They are usually serious mountaineers, explorers, backpackers, and hikers. For everyday hikers and people who enjoy outdoor activities occasionally, the tent is the preferable option.
Weight- Clearly, a bivy sack weighs much less than a tent as it is smaller and is designed for ultralight outdoor activities. This is an advantage for those who are covering long distances, walking through difficult terrain, or climbing.
Protection from the Elements- The design of a bivy sack will protect your sleeping bag from the rain. However, if it has eye or mouth holes, it may allow some moisture to enter. A modern bivy sack will usually have a highlevel of water-resistance. Tents keep you out of the wind and the best tents also have a high level of water-resistance.
Warmth- Bivy sacks will increase the insulation of your sleeping bag by approximately ten degrees. Generally, a tent will offer more warmth
Assembly- Bivy sacks win hands down as there is no assembly required. On the other hand, tents need varying amounts of assembly depending on their size and design.
Space- A tent clearly has much more space than a bivy sack. If you have gear to protect, stand in a shelter, and have living space, then a tent is the better option. A bivy sack has less space as it is intended only to keep you and your sleeping bag dry.
Experience- On the plus side, a bivy tent offers a true experience of spending the night under the stars for those who love the outdoors. On the downside, it is not the ideal way to get a good night’s sleep. In comparison, you have a better chance of sleep in a tent, but you will not have the same experience of being at one with nature.
Price- A bivy bag is usually much cheaper than buying a tent.
A Few Frequently Asked Questions
What is a Bivy Sack?
A bivy sack is the name commonly used for a bivouac shelter. Originally, these were a personal waterproof shelter that climbers used on excursions lasting several days. They are a lightweight alternative to tents and this has made them popular with ultralight backpackers, hikers, and mountaineers. They are a thin waterproof covering that lies over a person in their sleeping bag to protect them from the elements.
What Are the Benefits of a Bivy Sack and Why Use Them?
There are three main benefits of a bivy sack. The first is that they offer a way of protecting you from the weather while you sleep or when you just need to take shelter. The second benefit of having a bivy sack is that you can shelter from the elements quickly as they do not need assembly. The final benefit of having a bivy sack is that they are an ultralight form of shelter, so they are great for ultralight backpacking, trekking, hiking, climbing, and mountaineering.
Regardless of whether you want a bivy sack for ultralight backpacking or for use in an emergency, there are some excellent products available to suit all purposes and price ranges.
The best bivy sack for those on a budget is the Delmera Emergency Survival Sleeping Bag. Not only is this one of the cheapest, it is also suitable for use in an emergency for ultralight backpacking in the summer months, and for use as a sleeping bag liner in the winter.
The best bivy bag for regular use as an alternative to a sleeping bag when sleeping outdoors is the Outdoor Research Alpine Bivy as this has appealing features that improve the outdoor sleeping experience.
The best emergency bivy sack is the S.O.L Escape Pro Bivvy as this product is designed to protect a victim in an emergency rather than for general outdoor sleeping use.