Many bivy sacks weigh just a little over a pound, which makes them the lightest shelters available. I’ve never used one, but I don’t know of any good reason not to. They don’t seem to be very popular on long trails. Do they work okay?
I guess I could put my other gear in a garbage bag at night and cope with the limited sleeping space. But I don’t really understand how they avoid awful condensation problems in wet weather. Anyone have personal experience?
Eric
I use a bivy and its far from a perfect shelter- I think of it as an emergency shelter first and a camping shelter second. I tend to use shelters in bad weather. Condensation can build up inside especially if you have to close it up tight in a really heavy rain. The goal is to find a balance between ventilation (its not safe to zip mine up completely) and protection. I’ve managed pretty well in the 3000+ miles I’ve been using it, I’ve only had one night where I woke up in a puddle, usually I find just a little condensation along the ridge line. I must admit the last time I used it (last October) I felt it was time to get a tent.
Celt
a old versa-tech bivy from TNF.It’s breathable on top(water resistant but not proof)and coated bathtub bottom which extends up the sides a bit.It is not light,but I don’t need ground cover. Since I tarp,it keeps my down bag clean,keeps condensation and blown mist off,and adds a couple degrees to the temp.It breathes well and I never had a problem with that.It’s very long and if nesc could stuff my pack at the bottom to protect it.Oh yea it has a skeeter screen also.I don’t see them anymore but you could make one fairly easy I suspect.See you in the woods.Oo
Onlyone
ah, actually my tarp weighs 14 ounces… I don’t know about bivy’s other than both Gorilla Petes and Worms bivy gave up the ghost at the shelter right before Mahossuc Notch. They had OR gortex bivies.
Aswah
I hiked with a North Face bivy but decided it wasn’t for me in the long run. In cold weather, it was fine but in warmer temperatures it was like a hot-box. I didn’t like the fact that I had to leave my pack and other gear outside when it rained. Also, it was “hell” trying to set it up during a rainstorm. Big mess! Try re-packing in the morning during a rainstorm–a losing battle! I now use a one man tent for shelter, and it sure beats the bivy. Just my personal experience!
Ex-bivy man
Yeah, they work. Of course, that all depends on how you define work 
I used one on a NOBO thruhike this year and liked it for the most part. It’s really easy to set up and you can fit in really tight places. AFAIK, the only other thruhiker that used one for any length of time this year was Play. Last time I talked to Play about his, he was still happy with it and that was in Glasgow, VA I think. We both had OR Deluxe Bivys (the ones with a single pole) and Z-Rest pads. Play actually just rolled his whole setup (bivy, pad, and sleeping bag) up in one big roll to carry it, so it took no time at all. The thing that bugged me the most about mine was not being able to easily put boots on in the bivy in the morning while it was raining (happened a lot this year.) I didn’t have much of a condensation problem, the trick is to keep them open as much as possible, and keep your head as far ‘up’ as possible so that your breath doesn’t hit the solid fabric directly. One other thing that wasn’t fun about it was the fact that a bird can $hit on your face when you don’t have the solid door shut, I had that happen once and really didn’t like it. Mine still is in good shape except for the seam tape in one smallish place on the side. Good luck!
-S-
Skittles
If you sleep in shelters and the snow or rain blows in and gets your bag wet you will wish you had one. I use mine which is the O R verison in the shelters and under a tarp. It has always kept my bag dry and adds a little warmth on those cold and windy nights. As far as just using it as a shelter if it rains i would perfer to have a tarp over me and it.
frog
I have used bivies in the past, and I agree with the other posts - they’re lightweight, but cramped. Cramped also means you can set them up almost anywhere - between trees, in shelters, etc.
I like to hike with military-issue ponchos. With a poncho and a pair of gaiters you can hike through pretty heavy rains as long as the wind isn’t too strong. You can also wrap the front around you and snap/zip it to itself in the back, leaving the rear flap to cover your pack - this helps with the wind, also.
They also have grommets or tie points, so you can use them as a tarp to make a shelter with hiking poles or trees. Or you can use them as ground cover, which I do when I pitch my Hennessy Hammock on the ground (not recommended in a rainstorm…).
The ones with zippers work best as bivies (my current one is from Ecotat). You zip yourself inside, tie off the hood with the drawstring, and stay pretty dry. It’s 100% waterproof so condensation can be a problem if it’s completely zipped, but in a shelter you can zip the lower half (near the shelter door) and let the upper half hang open. Since it’s a big rectangle, there’s room inside for a small 5-6 day pack if you’re in a pinch. Ecotat also sells mosqito netting that zips into the poncho, but I haven’t found a place to buy the netting by itself.
Raingear, pack-cover, tarp, ground cover, bivy - for the versatility it can’t be beat. It’s a little heavier than a silnylon tarp, but it’s a lot more durable, too.
Jeff
Jeff
I brought my bivy with me on a section hike during June in Maine, which is (should have been) prime BUG season, and that was the only reason I took it. The bugs, for whatever reason, did not (or had already) put in an appearance those first few weeks down by Grafton Notch/Stratton, but as you can guess, the RAIN did . . . and I relived my hatred for bivies as the tent just got more and more damp, wet, soaked.
It is a Kelty Dart 2-man tent, which means if I’m having too much misery, I can always share it with someone I love…
:rolleyes
Kineo Kid