A portable shelter is very useful for multi-day outdoor adventures because it allows you to set up camp almost anywhere and anytime you like, rather than having to reach accommodation facilities like shelters and huts. Although tents are the most versatile and comfortable shelters, you might find a tent to be too heavy and bulky to carry it if you are alone – especially if you are out for only a couple of nights. On such trips a bivy sack is a great alternative to a tent because it is lighter and packs smaller. On average, a high-quality bivy sack is twice as light and 30 % smaller (packed size) than a high-quality two-person tent. Besides taking up less space in your backpack, it can also be set up very fast in case of bad weather. Bivy sacks are, however, not suitable for longer trips because they provide very limited comfort/space and often require that the backpack is left outside.
Here is our selection of the best bivy sacks. We only selected lightweight products which are made of waterproof/breathable materials because such bivy sacks provide the best versatility.
If you are undecided between getting a bivy sack or a tent, you should also check out our selection of the Best Backpacking Tents. If you want even more minimalistic portable shelter than a bivy sack, check out our review of the Best Lightweight Tarps. As for the comfort inside the portable shelter of your choice, we have also made reviews of the Best Sleeping Pads, and the Best Sleeping Bags.
1. Buying a Bivy Sack – What is important?
Lightweight equipment allows you to reach your goals faster and easier. As shelters are usually among the heaviest items of backpacking/hiking gear, a lightweight shelter can make a big difference in the weight that you carry. For example, a low-quality one-person tent can easily weigh as much as 6 pounds while a high-quality bivy sack weighs no more than 2 pounds. Read more about why it is important to use lightweight gear in our article Why hike lightweight.
Bivy sacks usually offer just enough space for one person. However, some allow you to suspend the material above the head which reduces the claustrophobic effect of the small shelter and thus increases your comfort. There are two different systems to suspend the material above the head area: The pole system and the flexible wire system. The pole system is very reliable but requires additional work when you are setting up the bivy sack because the pole must be inserted in the sleeve and secured. The flexible wire system is common on bivy sacks that have a relatively low head height. The wire in the head area stretches automatically when the product is unpacked and thus slightly suspends the fabric above the head.
Outdoor sports require gear that packs small because such gear enables you to pack more efficiently. Here we only listed bivy sacks that pack small.
All bivy sacks in this review are made of waterproof/breathable (WPB) fabrics such as Gore-Tex, eVent and Pertex. These fabrics are also used for rainwear and as you probably already know, WPB rainwear is never completely waterproof. The same goes for bivy sacks. Bivy sacks are water resistant but in heavy rain they will eventually leak. The main advantage of bivy sacks in comparison to ordinary tents is that they are completely sealed shelters. Therefore, they provide better weather protection in windy conditions and snowstorms. WPB fabrics are always treated with DWR, so they repel water. DWR must be reapplied from time to time for optimal performance. To learn more about waterproof/breathable fabrics check out the Hardshell section in our Comparison of Shell Materials. The floors of bivy sacks are made of polyurethane-coated nylon for better durability and complete waterproofness.
Weather and Condensation Resistance:
The weather and condensation resistance of a shelter greatly depend on the fabric. Unfortunately, the two qualities are mutually exclusive to some extent. The higher the breathability of the fabric, the better the condensation resistance as it allows moisture and warm air to escape to the outside. However, there is no such thing as highly breathable fabric that is also completely waterproof. Therefore, manufacturers have to find the right ratio between breathability (condensation resistance) and weather resistance in order to achieve the best functionality.
In general, bivy sacks offer inferior rain and condensation resistance in comparison to double-wall tents (which are equipped with a completely waterproof fly that comes over a breathable canopy) but on the other hand they are also faster to set up and much lighter. We do not recommend using a bivy sack (or indeed a single-wall tent) in areas that are known for continuous heavy rain.
We only list top-tier products. Read how our selections of best hiking products differ from others here.
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2. The Best Bivy Sacks Review
- Black Diamond Bipod Bivy
- Black Diamond Spotlight Bivy
- Sierra Designs Backcountry Bivy
- Rab Alpine Bivy
- The North Face Assault Futurelight Bivy
|Feature/Product||Black Diamond Bipod Bivy||Black Diamond Spotlight Bivy||Sierra Designs Backcountry Bivy||Rab Alpine Bivy||The North Face Assault Futurelight Bivy|
|Packed Weight||2 lb. 2 oz.||1 lb. 7 oz.||14 oz.||1 lb.||15 oz.|
|Packed Weight (Metric)||975 g||660 g||400 g||470 g||420 g|
|Packed Size||6 x 13 in.||4 x 7.5 in.||10 x 4 in.||4.7 x 12 in.||6 x 12 in.|
|Packed Size (Metric)||15 x 33 cm||10 x 19 cm||25 x 10 cm||12 x 30 cm||15 x 30 cm|
|Size (Length/Width)||92 x 30 in.||92 x 30 in.||80 x 36 in. (R), 86 x 40 in. (L)||93 x 31 in.||103 x 34 in.|
|234 x 76 cm||234 x 76 cm||203 x 91 cm (R), 218 x 102 cm (L)||235 x 80 cm||261 x 86 cm|
|Material||3-layer ToddTex||Single-layer NanoShield||20-denier Nylon Ripstop (WPB)||3-layer eVent||3-layer Futurelight|
|Head Area System||Single-Pole System||Single-Pole System||None||None||Free-Standing ( Flexible Wire|
1. Black Diamond Bipod Bivy
- Alpine Climbing
The Black Diamond Bipod Bivy is very popular with hikers and mountaineers because it provides superb performance but is also super lightweight – it weighs merely 2 pounds. It is made of a 3-layer ToddTex fabric which offers great tear- and abrasion-resistance. It also provides good weather protection and breathability. Due to high-quality fabric, condensation issues are rare with this bivy sack. The floor is made of resilient nylon for increased durability and water resistance. The Black Diamond Bipod Bivy allows you to suspend the fabric above the head with the pole. The pole comes in the sleeve and can be easily secured at the bottom. The bivy sack is also equipped with stake loops, and no-see-um mesh to keep the insects out. The Black Diamond Bipod Bivy is perfect for hikers, mountaineers and backpackers who want a reliable shelter for their adventures.
2. Black Diamond Spotlight Bivy
- Alpine Climbing
The Black Diamond Spotlight offers similar space as the Bipod bivy mentioned above. However, it is made of thinner and less sturdy fabric. The upper part of the Spotlight is made of a single-layer Nanoshield fabric (developed by Black Diamond) while the floor is made of durable abrasion-resistant nylon. The bivy sack comes with one DAC Featherlite pole which allows you to suspend the fabric at the head. When the head area is suspended the Spotlight offers an internal height of 51 centimeters which is indeed good for such a light and small (packed size) shelter. The bivy sack is also equipped with four stake loops and a no-see-um mesh door to keep the insects out. The main benefit of this bivy sack is that it’s extremely light and the downside is that the Nanoshield fabric is not as breathable as the ToddTex fabric. Therefore, condensation issues are more likely with this bivy sack.
3. Sierra Designs Backcountry Bivy
- Alpine Climbing
- Emergency shelter
The Sierra Designs Backcountry bivy differs from the products listed above in design. It is a very minimalistic bivy sack and thus perfect for use as an emergency shelter. Nevertheless, the bivy offers enough space to put in a sleeping pad and has a large u-shaped opening. At the head it has a mesh window panel which enables you to increase the ventilation in dry conditions. This mesh window panel is also very useful for preventing the condensation build-up. The top of the bivy sack is made of WPB 20-denier nylon while the floor is made of more robust 30-denier nylon. The main advantage of this bivy sack is its weight and packed size. It weighs merely 14 ounces and takes very little space in your pack. The Sierra Designs Backcountry bivy is best for those who want a minimalistic but very reliable shelter for trips in all conditions.
- Small when packed
- Window panel
- Easy to set up
- More likely to cause condensation issues
Where to buy?
Also available at:
4. Rab Alpine Bivy
- Alpine Climbing
- Emergency shelter
The Rab Alpine is another high-quality minimalistic bivy sack. It is best for demanding trips where lightweight and highly reliable equipment is required. It is made of a 3-layer eVent material which is very breathable and provides good weather protection. The Rab Alpine bivy sack has a durable floor which is reinforced with 70-denier nylon. Unlike some of the other bivy sacks on this list, the Rab Alpine is not equipped with a system to suspend the fabric in the head area – it has a completely minimalistic design. However, it is mummy shaped to fit technical sleeping bags. Even though it offers very little space, condensation is rarely an issue as the eVent fabric provides great breathability. The Rab Alpine bivy sack is primarily designed for alpinists, and works best in tough winter conditions (snow).
5. The North Face Assault Futurelight Bivy
- Alpine Climbing
- Emergency shelter
The North Face Assault Futurelight is another very minimalistic bivy sack. It weighs a tiny bit more than the Sierra Designs bivy mentioned above but it also has a Delrin reinforced brow which suspends the fabric at the head for more comfortable nights. The bivy sack is also equipped with bug net for use in warm conditions and has a fully waterproof closure for rainy weather. It has a square shape and thus offers a bit more space at the legs. This allows you to put in your footwear or a small backpack. The bivy sack is made of North Face’s proprietary Futurelight fabric. The Futurelight fabric consists of a face fabric, liner and a waterproof/breathable membrane. It provides good breathability and weather protection. The North Face Assault Futurelight bivy is best for those who want an emergency shelter or a minimalistic shelter for overnight adventures.
3. Questions and Answers
What are bivy sacks used for?
Bivy sacks, also called bivouac sacks, are one-person water-resistant shelters. Initially they were mostly used by alpine climbers on expeditions, due to the low weight and small packed size, Nowadays they are used by hikers, mountaineers, backpackers and other outdoor enthusiasts. A bivy sack is a lightweight and more compact alternative to a one-person tent.