What are the Best Bivy Sacks for Backpacking?

Bivy sacks are extremely small shelters which were invented as an alternative solution to heavier tents. They fit only one person and are a more minimalist option than most outdoor survival shelters. This makes them a great option for backpackers who need to travel as lightly as possible while remaining warm and dry at night.

This article will review the following five products, which are some of the best bivy sacks for backpacking:

• Outdoor Research Helium Bivy Tent
• Sierra Designs Backcountry Bivy
• MSR E-Bivy Emergency Shelter
• Rab Alpine Bivi
• SOL Escape Bivvy

Best Bivy Sacks for Backpacking Buying Guide

Weight

Choose a product that is lightweight. Bivy sacks are already lightweight because, unlike tents, they don’t include many hard structural components. Look for a bivy that weighs under 2 lbs. and can be packed down extremely small to save on space and make traveling easier.

Waterproof

Choose a product that is waterproof. You don’t want to be waking up in the middle of the night freezing cold and wet. Look for waterproof materials like polyurethane-coated nylon. This will protect you from harsh weather throughout the night.

Structure

Choose a product that is low to the ground. If a bivy sack features structural components that are too high, they may be affected by strong winds and collapse. The shorter a structure, the less likely it is to be affected by a storm that may head your way.

Ease of Setup

Choose a product that is easy to setup. Backpackers know that bad weather can often hit without much warning at all. Choosing a bivy sack that is simple to setup allows you to have immediate shelter in case of emergencies.

Durability

Choose a product that is durable. Looking for materials such as nylon or anything that is resistant to rips will save you money in the long-run and ensure your bivy sack remains warm and dry for years to come.

Ventilation

Choose a product that is breathable. Make sure that the bivy sack you’re buying is well-ventilated with breathable fabrics. If it isn’t you may find yourself dealing with uncomfortable condensation build-up.

Benefits and Advantages of Using a Bivy Sack

Bivy sacks are a great option for backpackers. They are more compact and lightweight than an entire tent but provide far more warmth and protection than a hammock.

One great advantage of traveling so lightweight is that you’ll be able to hike a greater distance in a day than you would if you were carrying around an entire tent. Additionally, the small packed down size affords you much more room for other useful gear that you may have otherwise been forced to leave behind.

Despite their size, bivy sacks offer comfort, warmth, and protection from weather that is comparable to and often superior to what’s offered from an entire tent. They are specifically designed to remain dry and wind-proof. The compact size actually helps keep your body heat close to you throughout the night, unlike tents.

Bivy sacks also have their advantages in warmer weather. Instead of sleeping in a closed-off tent, bivy sacks allow you to sleep right beneath the stars. They can be unzipped if you want more fresh air and give you the full sleeping outdoors experience.

Best Application for a Bivy Sack

Like it was mentioned above, bivy sacks are best suited for lightweight and minimalistic backpackers. However, they are also great to have on-hand in emergency situations or as a backup to your tent or other shelter.

Hikers or campers who are only going to be outdoors for a day or two can probably use a full-size tent without being held back by the shelter’s weight. Bivy sacks are intended for those who have long distances to travel over longer periods of time.

What to Avoid in a Bivy Sack

Don’t ever buy a bivy sack that isn’t durable and waterproof, unless you plan on using a tarp as a makeshift shelter as well. If water gets into your bivy, it will stop effectively holding in your body heat.

Additionally, an overly wet bivy sack can begin to mildew and smell over time. Keep in mind that a bivy typically lays directly on the ground, so materials like cloth or untreated fabrics may rip on rocky terrain.

It is also a good idea to avoid bivy sacks that don’t feature a sizable zipper. If a bivy cannot be opened partially, then you’ll have a difficult time airing it out between uses. This allows for moisture build-up due to condensation and can render your bivy useless in cold weather.

Outdoor Research Helium Bivy Tent

The Outdoor Research Helium Bivy Tent is a standout choice for adventurers who prioritize minimal weight without sacrificing essential features. Weighing a mere 18.6 ounces (including the stuff sack), it comfortably meets the sub-2-pound requirement, making it an excellent companion for both bikepacking and backpacking trips where every ounce counts.

Crafted with high-quality waterproof and breathable materials, this bivy ensures you stay dry and comfortable in unpredictable weather. The fully taped seams and Pertex Shield+ fabric offer robust protection against rain and moisture, preventing any unwelcome leaks during the night. Its low-to-the-ground design, complemented by a single shock-corded pole at the head, maintains a sleek profile that resists strong winds and minimizes the risk of collapse during storms.

When it comes to setup, the Helium Bivy shines with its simplicity and speed. The straightforward design allows you to pitch it in mere minutes—a crucial advantage when setting up camp under looming dark clouds or after a long day on the trail. Durability is another strong suit, as the bivy’s rugged construction is designed to withstand the rigors of the outdoors, ensuring it remains a reliable shelter for years to come.

Ventilation is thoughtfully addressed with a bug net that promotes airflow on dry nights, helping to mitigate condensation buildup inside. At 82 inches in length, it provides ample room for taller users, enhancing comfort without adding unnecessary weight. The only minor drawback is the absence of a side zipper, which might make entry and exit slightly awkward for some. However, this is a small trade-off considering the bivy’s overall performance and protective features.

Sierra Designs Backcountry Bivy

The Sierra Designs Backcountry Bivy is an inviting option for those who desire a bit more space and comfort in a compact shelter. Weighing in at 1 pound 15 ounces, it remains well under the 2-pound mark, striking a balance between weight and roominess. This bivy is particularly accommodating for backpackers using thick air mattresses or cold-weather sleeping bags, thanks to its generous dimensions.

Constructed with a waterproof and breathable fabric featuring a Durable Water Repellent (DWR) finish, it offers reliable protection against the elements. The fully taped seams enhance its waterproof capabilities, ensuring you stay dry during unexpected showers. Its minimalist, pole-free design keeps it low to the ground, reducing wind resistance and enhancing stability during adverse weather.

Ease of setup is a highlight, with a straightforward process that gets you sheltered quickly—an essential feature when sudden rain demands immediate action. The U-shaped zipper provides convenient access, while the mesh panel significantly improves ventilation, promoting airflow and reducing condensation inside the bivy.

Durability is commendable, with robust materials designed to withstand the challenges of backcountry use. However, some users have reported condensation issues, particularly around the non-breathable yellow patch at the foot box. This is an area where the bivy could see improvement to enhance overall comfort.

While the lack of a side zipper may make entry and exit a bit challenging, the bivy’s overall performance, spaciousness, and protective features make it a strong contender for backpackers seeking comfort without a significant weight penalty.

MSR E-Bivy Emergency Shelter

The MSR E-Bivy Ultralight redefines minimalist shelter for adventurers who value every ounce in their pack. Weighing a feather-light 6 ounces (170 grams), it’s designed for ultralight backpackers and fast-packers looking to push the limits of weight reduction without sacrificing crucial weather protection.

Made from 15D ripstop nylon with a water-resistant, breathable coating, the E-Bivy offers just enough protection to get you through light showers and damp conditions. While it’s not built for long-term exposure to heavy rainfall, it excels at keeping you dry in a pinch, while allowing moisture to escape to reduce condensation—perfect for short, fast-paced trips or as an emergency backup.

The E-Bivy is all about simplicity. There’s no need for poles, stakes, or complex setups—just unroll it, and you’re ready for shelter. This ultra-fast setup makes it a great option when you’re short on time or energy, whether you’re in an emergency situation or just want to crash quickly after a long day. However, the stripped-down design does come with a trade-off: limited space. It’s compact and low to the ground, so while it serves its purpose, it’s not going to be the most comfortable spot for extended stays.

Ventilation is adequate thanks to the breathable fabric and a small opening near the head area, but don’t expect complete relief from condensation in humid or cold conditions. It’s functional but minimal, so moisture buildup is a possibility during extended use in less-than-ideal environments.

Durability, as with any ultralight gear, is something to consider. The 15D nylon strikes a decent balance between weight and toughness, but it’s not indestructible. You’ll need to be mindful of where you set up and how you handle it to avoid tears or punctures. This bivy is best for those who know how to take care of ultralight gear and are willing to accept the compromises that come with shedding as much weight as possible.

In short, the MSR E-Bivy Ultralight is perfect for serious ultralighters who value simplicity and minimal weight above all else, but it requires careful handling and is best suited for short trips or emergency situations.

Rab Alpine Bivi

Designed for the demanding conditions of alpine environments, the Rab Alpine Bivi is a high-performance shelter that doesn’t compromise on protection or durability. Weighing approximately 20 ounces, it remains under the 2-pound threshold, offering a balance between lightweight portability and robust construction.

The bivy is made with eVent® DVStorm 3-layer fabric, renowned for its exceptional waterproofing and breathability. This advanced material ensures you stay dry during heavy rain or snow while effectively venting moisture from the inside, significantly reducing condensation—a common challenge in bivy camping.

Its minimalist, pole-free design keeps it close to the ground, enhancing stability against strong winds and reducing the risk of structural failure during storms. The wide opening, equipped with a two-way zipper, allows for versatile ventilation options and easy access, even when wearing gloves or in tight spots.

Setting up the Alpine Bivi is straightforward and quick, a crucial advantage in unpredictable mountain weather where time is of the essence. Durability is one of its strongest attributes; the high-quality materials and meticulous construction are designed to withstand the harsh conditions of alpine expeditions, ensuring reliable performance when you need it most.

Ventilation is excellent, thanks to the breathable eVent fabric and the adjustable zipper, which allow you to tailor airflow to your needs, enhancing comfort and reducing condensation.

While the Rab Alpine Bivi comes with a higher price tag, it’s a worthy investment for serious adventurers who require dependable protection in extreme conditions.

SOL Escape Bivvy

The SOL Escape Bivvy is an ultralight, versatile shelter designed primarily for emergency situations but adaptable for minimalist backpacking. Weighing a scant 8 ounces, it’s one of the lightest options available, making it an attractive addition to any pack, whether for planned adventures or unexpected overnight stays.

Constructed with a proprietary fabric that reflects body heat while allowing moisture to escape, the Escape Bivvy provides essential warmth and basic protection against the elements. It’s water-resistant rather than fully waterproof, meaning it can handle light precipitation but may not keep you dry in heavy or sustained rain.

The structure is as simple as it gets—no poles, zippers, or additional components—keeping it low to the ground and highly resistant to wind. This simplicity also means setup is instantaneous, a critical feature in emergencies when every second counts.

Durability is modest, suitable for emergency use or occasional ultralight trips. The materials are not designed for regular, rugged backpacking, so care should be taken to avoid tears or punctures.

Ventilation is surprisingly effective for such a minimalist shelter. The breathable fabric helps reduce condensation, maintaining a more comfortable interior environment than traditional emergency blankets or bivvies.

In conclusion, the SOL Escape Bivvy excels as an emergency shelter and is a viable option for ultralight enthusiasts willing to accept its limitations in exchange for minimal weight and pack size.

Conclusion

In the quest for the perfect night’s sleep under a canopy of stars, choosing the right bivy sack can make all the difference between a restless night and a rejuvenating outdoor experience. After trekking through the features, benefits, and nuances of the top bivy sacks on the market, it’s clear that there’s a perfect match for every type of adventurer.

Whether you’re a minimalist hiker counting every ounce, a seasoned mountaineer braving alpine conditions, or a weekend warrior seeking solace in nature, the right bivy sack enhances your connection with the great outdoors while providing essential protection and comfort.

The Rab Alpine Bivi stands out as a pinnacle of design and functionality, offering unparalleled durability and weather resistance for those facing the harshest elements. For those prioritizing a balance of lightweight design and robust features, the Outdoor Research Helium Bivy Tent delivers reliability without weighing you down. If extra space and comfort top your list, the Sierra Designs Backcountry Bivy provides a roomy refuge without straying far from the packable convenience that bivy sacks are known for.

Ultimately, the best bivy sack is the one that aligns with your adventures and personal preferences. As you prepare for your next journey—be it scaling towering peaks, navigating dense forests, or simply escaping the hustle of daily life—equip yourself with a shelter that’s as ready for adventure as you are. Embrace the simplicity, relish the intimacy with nature, and let the stars be your nightlight. Happy trails and restful nights await!