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Vapr Quantum Bivy Sack

Vapr Quantum Bivy Sack

A waterproof bottom and breathable top make this 6.5 ounce bivy sack useful for tarp camping and sleeping under the stars.

Overview of the VAPR Bivy Sack

The VAPR Bivy Sack is an ultralight and feature-rich bivy sack. With a waterproof silicone-coated nylon floor and a (water-resistant) breathable Pertex Quantum upper, the VAPR Bivy Sack is one option for tarp campers, winter hiking enthusiasts, and others who value the ability to keep their sleeping bag dry and protected from rain spray, condensation dripping, and spind drift. The VAPR Bivy Sack was designed to be used in conjunction with another overhead shelter (or as a standalone shelter in sub-freezing, very dry conditions).

Application Notes

From customer Jeff Price:

Here's a great tip from VAPR Bivy owner Jeff Price:

"I actually attached some short pieces of shock-cord to the stake-out and hood loops to provide some margin of error..."

Adding shockcord will result in less stress on the tie-out seams if you decide to stake the floor taut and extend the life of your bivy sack.

From BPL Publisher Ryan Jordan:

This is my favorite piece of gear. It's a perfect mate to a sleeping quilt, and offers more versatility than a sleeping bag with a more water resistant, but less breathable shell. The Vapr Bivy replaces a ground cloth, can be used for winter camping in a tent or snow cave, and the hood can be lifted high with a cord for mid-summer camping in mosquito country.

I used the VAPR Bivy under a tiny poncho tarp (4.25' x 7.75') while backpacking California's Lost Coast in April during conditions that could only be described as sopping wet. The bivy kept wind-blown rain spray at bay, and the Pertex Quantum top was breathable enough that even my wet clothes and wet sleeping bag grew drier through the night (caveat: we had temperatures in the 40s and 50s, so don't expect this to happen - with any bivy - as temperatures dive to near freezing).

FROM RYAN'S LOST COAST JOURNAL, APRIL, 2004 - "Being wet had taken its toll. These were the wettest and stormiest conditions I've ever used the Quantum Arc X - Quantum Vapr Bivy - SpinPoncho combo. This night, I would boil some tea and then crawl into bed for a few hours in the evening. I wore wet polypro long johns (I kept my sopping Cloudveil Prospector pants out of the bag tonight, although I'd worn them wet to bed the previous night), a mostly wet Smartwool long sleeve zip-T, and a fairly damp Cocoon Pullover to bed. My only dry clothing that I wore to bed was my fleece socks, which stayed dry under the poncho, inserted into the shoulder straps of the (Gossamer Gear) G5 (Backpack) as padding. After my two hour nap, I woke up and everything inside was really wet - the bivy was a condensation station like I've never seen, and my down bag was getting soggy. Now here's the surprising part. By morning, all was pretty dry. Clothing was dry, bag had restored some loft, and there was no condensation in the bivy. This was one of the more remarkable observations I've ever seen in the backcountry, and gave me a whole new level of confidence of dealing with down in wet conditions. The key, I think: reasonably warm night time temperatures (48-52 degrees; note that outside humidity was 100%) and ultrabreathable shell fabric on both the bag and bivy: Pertex Quantum. This observation made the entire trip worthwhile."

I pair the Vapr Bivy with an Arc X sleeping quilt, which is a lightweight, versatile, and very weather worthy sleep system for tarp camping. I've used this system with a small poncho for everything from wet weather camping on the Lost Coast to heavy snow in the Wind River Range.

From customer Dan Healy:

"Ryan - The shot with the Hex is at a very wet place called Rat a Tat in the Lamington National Park in south east Queensland Australia. It is a subtropical rainforest and in winter, when this shot was taken, it is quite cool around 5 or 6 Celsius and very damp. Amazing vegetation though! There are Antarctic Beech trees that are surviving from Gondwanaland times, spotted tiger quolls – a ferocious cat sized marsupial that have an eerie call at night. The shots of the bivies in the open are at Running Ck in south east Queensland. It is an out of the way spot that always has running water. A bit of a bush bash to get into but that is standard in this part of the world. The Bivys have been tremendous – a real highlight of the gear list! Thanks again!"


  • Silicon-coated nylon bathtub floor is waterproof in 99% of the wet conditions we've faced.  Wetter conditions would be more comfy by sealing the floor seam.
  • Four grosgrain ribbon stake-out loops at corners to keep bivy in place during the night.
  • Contoured footbox and box bivy body to prevent compression of sleeping bag loft, even for winter bags.
  • Cross-chest traditional bivy opening (zippered) to save weight.
  • Large hood provides plenty of room for gear storage, pillow, etc. Some of our customers even purchase the long size bivy and store their ultralight packs in the hood.
  • Grosgrain loop at top of hood can be tied (e.g., to the peak of your tarp), providing extra headroom while in the bivy to prevent that non-lovin' claustrophobic feelin', and heck, you can even read inside - more room than you think! Also improves ventilation significantly.
  • Zip-out noseeum mesh window can be left in for buggy conditions, zipped fully open for maximum ventilation, or simply left at home to save weight. With the window zipped out, the chest zipper of the bivy still zips shut for maximum storm protection and warmth. This versatility is accomplished through no slight magic of technological zipper wizardry.


  • Lengths:
    • Regular: fits sleeping bags up to 6’0”
    • Long: fits sleeping bags up to 6’6”
  • Weights: 
    • Regular: 6.7 oz (189.9 g)
    • Long: 7.2 oz (204.1 g)
    • Netting Window: 1.2 oz (34.0 g)
    • Stuff Sack: 0.4 oz (11.3 g)
  • Max Girth: 76 in (193 cm)
  • Shoulder Diameter: 37 in (94 cm)
  • Foot Box Diameter: 33 in (84 cm)
  • Colors:  Vary based on fabric availability, but muted
Size: (Will update display)


Regular Price$229.99
Member Price$218.49
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