Let's talk bivys. Good ones, and cheap ones.

Jimro said:
The only bivy's I have experience with are the Army issue Gortex, in both the original woodland pattern MCSS (modular component sleep system) and the new ACU pattern.

The Gortex cover is "mummy" style so that you don't have to completely cover your face, but you can if you want. The only condensation problems I've ever had come from my breath hitting the gortex and me rolling into it. No problems at all with my body getting wet, only a small patch in front of my face.

Never tried a non Army issue sleep bag inside the bivy cover, but I don't see how it would work any different.

Jimro
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So you were sleeping inside with no additional insulation beyond the clothes you were wearing? Anybody else use only the bivy? How cold did it get before you became uncomfortable?

I am curious as I'm considering adding one to my SAR gear as a barrier to the cold and wind. Mainly I just sleep in my clothes and throw a heavy duty emergency blanket over myself when overnighting in the field. A fire may or may not be an option depending on location and time of year. Weight is a big issue for SAR ops and the less weight we have to carry the better. In some ways we are like minimulist hikers except we also have to be able to carry mission specific gear or injured patients in addition to our own gear. We also have to be able to manuveur across difficult terrain and cross country mobility can be impacted by heavy/bulky gear. My current set up weighs close to 35lbs already. I don't want to add more weight if I can avoid it but need a more comfortable means to spend an unplanned night out.
 
James, a bivy sack will be of very little use against the cold unless you couple it with some form of insulation fron that heat-sucking ground Z-Rest, cedar boughs, something. Once you're insulated from the ground, having the bivy sack to protect you from the wind will substantially increase your comfort level.

-- FLIX
 
Thanks Flix. I was looking for some first hand experience from anybody that as used it without a sleeping bag inside.

I've got about 20 years of camping/backpacking experience just never have used a bivy outside of the military. I got out in 99 and used the one that was issued to me twice maybe three times and have no hands on expereince with what is currently available. I have a very small budget to purchase new gear with so I was looking for some information before I make a major purchase. I know all about insulating from the ground and improvised shelter building. What I was hoping is that I can improve my overnight comfort without adding much more weight to my gear. One of the things about SAR gear is that most of it is outside of what a normal backpacker would carry. It is more along the lines of what military personnel carry. 90% of it is mission required or survival gear with the remaining 10% dedicated to personnel comfort. I would go into detail but it would be extensive and off topic.

Maybe I'll start a thread discussing SAR gear if there is enough interest.
 
Its intresting to know do you guys use the insulating pad inside the Bivi or under it???
 
All the bivvy designs I have seen expect you to place your pad between the bivvy and your sleeping bag. I.e. inside the bivvy.
 
sasha said:
Its intresting to know do you guys use the insulating pad inside the Bivi or under it???
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I've tried both ways and prefer it on the outside, between my bivi and ground. It just gets a little too cramped inside, although it does stay in place much better. Regardless of what bivi and sleeping bag system you use, I still recommend a small siltarp for overhead cover; if anything it keeps your boots and gear dry and allows you to do a few small camp chores without getting rained on.

ROCK6
 
I found a huge tent that someone tossed in the garbage. I took the rain fly off it and now i got a great tarp.
 
James 61 said:
So you were sleeping inside with no additional insulation beyond the clothes you were wearing? Anybody else use only the bivy? How cold did it get before you became uncomfortable?
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Bivy alone doesn't add any insulation per se. And it obviously doesn't prevent heat loss by conduction.

Where it really shines is against wind. Since most bivys are waterproof they are perfectly wind proof. The more wind you get, the more the bivy is valuable.

In places where there is a lot of wind, notably mountain, I would favor a bivy (completly enclosed, no flapping in the wind). In places with more cover (thick woods...), I would favor a poncho (more durable, more versatile, less wind protection).

A bivy is just like a shell in a layered system, think about a goretex jacket: doesn't keep heat but protects insulation below.

Army bivy bags (british, US...) are efficient and durable, but they are so heavy they compare with tents which are inherently better...
 
As an emergency setup, I carry a Cabelas XPG bivy and a Sea to Summit reactor fleece liner - not too warm, but will retain some btu's and keep the rain off.

B
 
Personally I couldn't find a Bivy I liked, so I made one from a 10'x8' peice of tyvex that was going to be thrown out at a construction site. Not great, but it works. Coupled with a poncho it is enough to protect from the rain decently. I made a hoop out of broken tent pole from one of my EMS 4 season tents. Very light weight and fits quite nicely in my get home bag. NOT for heavy weather use.
 
I have a North Face bivy,I paid a good amount of money for it, But it was the thing to have when your sleeping a couple thousand feet off the ground when climbing a rock face,Do i think it was worth it? No, I sweat my butt off in it,To tight,just a real pain in the butt getting in and out of,I tried it on some wildfires,and the same thing just to tight for me,It may just be the one i got,For wildland fires,I use a heavy space blanket,its almost like a tarp,they run around 12 to 20 dollars,They do have eye holes to be used as a tarp if you like,I fold it up so it will fit in between my pack and my back,So it acts like a pad for me, I carry around 40 pounds on my back all day,While digging a fire line.I do also carry a Snugpak sleeping bag,It fits in the palm of my hand,and its like a insulated bivy,For those really cold nights,Yes there is some really cold nights on wildland fires,Every year i get snowed on,while fighting fires.Alot of times your heli drop in to a place were theres nothing for miles, to find out your staying for a couple of days,Since a storm is coming in,and the chopers cant come get you,So i use the space blanket for a tarp and build a fire.It works for me,I have done this many times a year,for 7 years
 
Thanks for the responses. I figured a bivy had little to no insulation value but wanted to hear people who have actually used them more than I have.

Ravaillac - Thanks for the detailed info. Carrying a tent is not an option so carrying a heavy bivy would not be an option either. A light weight bivy would be so I'll have to look around.

brians - how cold did it get before your combination became unberable? I like the idea of your set-up and am considering it. That or one of the snugpaks RX Fire mentions

RX Fire - I've got one of those emergency blankets and have carried it for years. It holds condesation however. It works ok but I'm looking for something breathable and with some minor heat retention properties. I use a 10' x 10' treated nylon tarp for overhead cover. It is less bulky and feels lighter than the blanket and makes a far better shelter. I'm trying to shave both weight and bulk but maintain or improve capabilites. Like you we are carrying lots of gear that would not be carried by the ordinary hiker and need to shave every ounce we can.
I have a Land Shark bag that was one of freebies I got when I took an aircrew survival course through the state. It's still in the wrapper. I guess I'm saving it for a true emergency instead of routine missions.
I'll have to look into a snugpak also. Any suggestions?
 
James 61 said:
Thanks Flix. I was looking for some first hand experience from anybody that as used it without a sleeping bag inside.
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Been there, hated that. About a month ago I went out to play "UNO", that is, to practice an Unplanned Night Out. No sleeping bag or pad. I was under a tarp, with an emergency Bivy Sack and a foil (bubble wrap)windshield shade under me. As luck would have it, the many days of rain was broken and I had a beautiful, clear night. It also got into the low twenties!!! :eek:

I got so little sleep I would have been much more comfortable sitting up and feeding the fire all night. I am convinced that I would have been MUCH warmer if I had better ground insulation. It was my first test using the windshield shade. I had been confident that it would provide a good break between me and the ground, but that wasn't the case. My next test will be with the bivy and a proper pad.

-- FLIX
 
Hey James,the snugpak i use is a Softie Chrysalis Kilo,it weighs alittle over 2 pounds,which isnt that much for me,and it goes somewhere down to the low30s comfortly,I agree you do need some kind of bedding to lay on,or it wont be worth anything,I think the bag ran me around $120,I dont know your price range.You sar guys do carry alot more gear than we do,I have a couple of freinds that work with windriver sar team,and they carry alot of gear.For me its as much water i can carry,a good amout of food,then some basic stuff like blanket,snugpak bag,matchs,radio,bennie,lots of batteries,sweat shirt,bug spray,compass,map,gps,mirror,rain pancho,extra gloves,small first aid kit for my self how i want it and what i need,small knive and thats about it,for me thats all i need,than again,when were spiked out, they fly us mres or 5 gallon buckets of eggs or steak,what ever they decide is for breakfest or dinner:barf: We have someone supplying us,Unlike you SAR Teams
 
Flix - Thanks for sharing your experiences with equipment combos. We practice the UNO twice a year. In Late Sept while the weather is still faily decent and then again in Jan or Feb. The Jan/Feb is done in the snow usually 6+ feet of it. That one is usually more sleepless than the others. Last year I got to do it twice. A two nighter in June up near Snoquinee Pass without fire and a one nighter in late Sept up above Carson with fire. Having a fire makes a difference. I missed the snow one this Feb due to a nasty sinues infection. Decide staying home was better than getting even sicker.

RX Fire - I've worked with the Wind River guys quite a bit over the last couple of years. They are a great bunch. I guess I don't need to explain to you then about keeping it light. Sounds like you carry quite a bit too. Unfortantly we don't have the logistical support you guys have so we get to carry our own food and water plus other mission specific gear and/or patients.
Thanks for the snugpak info.
 
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