My own passion for camping with a bivy sack has less to do with saving weight and much more to do with its aesthetic appeal. Camping in a bivy sack seems to allow me to more deeply engage with the backcountry experience with simpler gear, greater mindfulness and intentionality in choosing and using my campsite, and the feeling that I'm closer to the natural world rather than separated from it by opaque layers of nylon.
In the old days, before there were many options for lightweight shelters, the bivy sack might have been considered an essential component of a lightweight backpacker's kit. A waterproof bivy sack can be used as a standalone shelter (especially when you pay attention to naturally-available overhead shelter options), or in combination with a small tarp.
The tarp-bivy combo in particular grew in popularity in the lightweight movement as lighter and more breathable materials became available. A small tarp made with Cuben Fiber and ultralight bivy sacks (i.e., those that are water-resistant and highly-breathable and not necessarily appropriate for standalone shelter in inclement conditions) comprise a combination that can easily weigh less than a pound.
When camping with a bivy sack, I prefer to do so without a tarp. In inclement conditions, of course, this requires a bivy sack that is fully waterproof. Many options exist, and are distinguished primarily by the type of floor and upper fabrics, whether or not they have taped seams, and the amount and type of pole structure used to increase livability and interior comfort.
Examples of luxury bivy sacks include the Integral Designs Nestor Bivy and the Nemo GoGo Elite Bivy. These types of bivy sacks include pole structure at both the head and foot end and are more like tiny tents than conventional bivy sacks. They typically weigh in the range of 1.5 to 2.5 lbs.
At the other end of the spectrum are bivy sacks with minimal or no pole structure, such as the Integral Designs eVENT Micro Bivy and the REI Minimalist Bivy. Such minimalist bivy sacks weigh in the range of 1.0 to 1.5 lbs.
It is in this context that we must now consider the Mountain Laurel Designs ("MLD") eVENT Soul Bivy. At 13 oz, the Soul Bivy is not the lightest waterproof bivy sack on the market (e.g., check out the Terra Nova Ultra Bivi which weighs a remarkable 50 g), but to my knowledge, it's the lightest bivy sack available today that provides some important features to the serious bivy sack camper:
- Fully Enclosed - a waterproof zipper system that prevents water entry into the bivy in inclement conditions;
- Highly Breathable - the use of highly-breathable eVENT fabric to minimize condensation (a common challenge with bivy sack camping);
I'll address both weather protection and breathability in this review, but first, let's start with a more detailed description of its feature set.
ARTICLE OUTLINE
- Introduction
- Features and Specifications
- Field Use
- Weather Protection
- Breathability
- Options
- Value
- Summary
- Product Strengths
- Opportunities for Improvement
# WORDS: 2160
# PHOTOS: 6
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Companion forum thread to:
Mountain Laurel Designs eVENT Soul Bivy Review
Thanks, Ryan!
One of my biggest gripes with using a bivy is vertical comfort as it is entirely too influenced by the type of pad I use. If I put anything other than a CCF pad, it is so tight on top from pad thickness that often I can't close the bivy. Course, I'm broad and very ogre-like, so this might only be relevant to those of us with an extra or missing a chromosome or two. Either way, sure would be nice to have a little wiggle room. One size doesn’t, and never will, fit all. I can also commiserate with the condensation issue. 20 and below with no wind is not good at all. 60’s and above in Virginia humidity is equally uncomfortable. I have a custom skunk-works bivy with a cuben bottom, waterproof/breathable cuben around the feet, and pertex from my knees to my head. Result – still lots of condensation.
As a bivy romantic, I am delighted to read this review. :)
Are there any care instructions for the bivy, e.g. washing it like a jacket to keep the eVent breathing? And might they cause any issues for the cuben or seam sealer?
I love my Miles Gear Pico bivy. Granted its 5 ounces heavier than the ML Soul, but at half the price it includes full seam sealing, a hoop, and enough room to read a book inside. It is very roomy, big down bag, down mat, and a down jacket on and the fabric is hardly in contact with the bag around my torso (I'm 5ft 11" and weigh 220 pounds). No condensation to date, water tight in stormy conditions. I can bring my pack to bed with me when the rain is sheeting down outside and stow it in the hood – no tarp required. The eyelid style hood with the large hoop also creates a profile that sheds water and prevents puddles forming. Available in any colour, so long as its white.
thanks much for the review, I'm purchasing one solely for multi-day running adventures and the eVENT sounds like the way to go
for hiking I'll stick w/ a light pyramid shelter :)
I have this bivy sack but haven't used it in a large range of conditions.
Past experience led me to add a semi-circle of fabric that covers the zip where my face is. This allows me to keep a good ventilation opening even in heavy rain.
I think the bivy sack is very good for the weight because
The wire keeps the fabric off my face and helps shedding water.
The large zip allows easy access
The netting keeps bugs away
The extra loops are useful for the reasons stated in the article
The eVent breathes well
The floor is waterproof
All the best,
Gordon
This is the kind of review that keeps me renewing my membership each summer. I appreciate you taking the time to test the bivy in varied conditions, and sharing your impressions on standard sizing, eVent vs cuben floor, and seam sealing vs taping.
After a lot of deliberation I placed a custom order for an eVent Soul bivy last November in long, extra wide (82" shoulder, 68" foot girth) with full length zip and cuben floor. I bought it primarily for winter use under a tarp, and wanted enough extra girth to avoid compression of a winter bag. Total weight came in right at 16oz. The first time out I used it in a snowstorm that my tarp couldn't keep at bay, and it came through with flying colours. So far I've used it in temps ranging between 10-25F, and I haven't noticed any condensation on my bag or inside the bivy each morning.
Regarding seam sealing vs. taping, my understanding is that the latter would add about 4oz to the overall weight if it was offered.
Ron was great to deal with throughout the custom ordering process. I wouldn't change any of the specs if I were to order this bivy a second time. I appreciate the extra space on long winter nights, and the ease of access with the full length zip.
…mainly in snow shelters. And an eVent bivy is (IMHO) the best of the lot.
As for the need to seam seal it myself, that's a minor "rainy day project".
Thanks for this review. Glad to find another source for an eVent bivy.
@Ryan,
Excellent review.
thank you
i have always loved bivys's and what they enable me to do.
for example i also love sea fishing for bass.
what other shelter allows me to scramble up sea cliffs and sleep out on ledges above the high tide mark? que amazing outdoor experiences!
An excellent review from Ryan as usual. It is nice to see an in depth review of an actual UL product here at BPL. Please, more like this and fewer bike packing, pack rafting, heavy pack hunting articles!
Timely as I've been thinking of returning to the single biv sack game for mostly solo (all the other shelters have had the Goldilocks problem of just bring a little off). Maybe a small cuben tarp for entry on a rainy day?
I've been drooling over this bivy for years but at $355 it's just not going to happen.
Craig, why not make your own? I'm not sure about currently, but in the past i've seen eVent material for sale, and bivies are about one of the easiest things to make. Would tend to be substantially cheaper.
Craig, for a smidge more weight, but much larger for a winter bag you could look at the ID eVent Micro Bivy
http://www.mec.ca/product/5022-263/integral-designs-event-microbivi-bivy-sack/?q=Bivy
$159
http://borahgear.com/eventbivy.html
Curious what other colors would folks like as a Soul Bivy option?
We may be able to get a second color option by splitting the dye lot on the next order.
Some folks also adding their votes for a second color on our FB page- looking like stealthy woodland/nature colors in the lede.
Thanks
Hi Ron,
Couldn't find your Facebook page, but I'd be very interested in a brighter colour for the top. I'm considering this as an alpine/emergency bivy, and visibility is valuable to me. Bright orange is appealing :-)
I have been looking into this bivy bag for a while now and my question is on the durability of eVENT vs. cuben for the bottom. Is eVENT a durable material? I am thinking of going with the eVENT for the floor but am concerned with leakage over time. Any thoughts? Also, what do you all think of sleeping pad placement…inside bivy bag or external to it? Any thoughts are greatly appreciated. Oh, I too would like to see an option for a hooped version.
I find the eVENT top plenty breathable on it's own, the cuben is lighter and appears to very tough
I like the pad in, that way you won't slide off the pad- I'd consider ordering the Large regardless of size, allows use in the winter w/ a higher loft bag, more room inside to store gear and not too big a hit on weight over the Regular
maybe someone w/ a eVENT bottom can also comment
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