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pgvoutdoors
12-30-2008, 09:47 AM
Bivy sacks are light weight and compact making them a popular choice for BOB's, but are they a good way to go?



What makes up a bivy sack and bivy shelter?
The basic bivy sack is nothing more than a waterproof sack, large enough to cover a sleeping bag.
A bivy sack differs from a bivy shelter as a shelter normally is a bivy sack with hoops at the head to create a small canopy over your head. This head area may include a screen panel as well as a waterproof cover.
Bivy sacks are normally used in winter camping, when the person is sleeping in a snow cave, igloo, or bottomless tent. They protect your bag from moisture and damage from the snow.

Bivy Shelters are normally for three season camping where the weather is more wet. It' main purpose is to protect you and your sleeping bag from the weather.



Disadvantages of a bivy shelter:
Used for sleeping only!
No room for gear
No room to change clothes
Can't sit up
Prone to condensation buildup (winter and summer)
Provide no cover to prepare meals
If you are constantly on the move and weight is a major concern, a bivy shelter can be a good choice. I personally dread using them, what do you think?

MCBushbaby
12-30-2008, 10:00 AM
Oh pgv, you're a real downer on the bivvy crowd :o

I'm happy with my MSS bivvy combo. Didn't get to test it in anything remotely cold (weather 'miraculously' went from 10F to 60F the days following it's arrival to my doorstep... grrr) but I'm enjoying trying it out in the hallway :P You can't beat the ease of setting them up. Keeping your sleeping bag in a bivvy when it's time to pack out, roll it up, shove it in the pack and trot off. At the next camp just unroll and you're good to go. Always free-standing, if you find that annoying rock under your *** once you lie down, just pick up and move. While everyone else will be fiddling in the dark with poles and stakes and ground sheets, you're halfways done with supper! I agree with the condensation, price to pay I guess. The MSS doesn't have bug netting either but I'll fix that come spring.

And bivvy bags with their fancy little head bubbles... bah! What are you going to do with that extra room? Read a book? Sissies

pgvoutdoors
12-30-2008, 10:06 AM
You made a very good point in pointing out the fact you need to leave your sleeping bag in the bivy sack. I've seen many people struggle in the rain unpacking their sleeping bag and trying to get it in the bivy.

DOGMAN
12-30-2008, 12:27 PM
I am a big fan of my OR Bivy. With a good bag and good bivy you can sleep anywhere. I like them for ease of use in winter camping with my sled dogs. I'll get my dogs all staked out. Build a fire, sit around that for awhile and cook and chill out, then crawl in the bivy near the dogs for a few hours then get up and get traveling. Its way easier than a tent or snow cave, and just as warm. Great for the solo winter traveler.

Ideal user for a bivy- people who are more interested in covering miles than camping out.

Don't get me wrong though- I do love a well set-up canvas wall tent with a wood burning stove. But, very time consuming to set up. Not too practical for someone making miles

jbone
01-12-2009, 07:40 PM
so are bivies really only for winter or could they be used year round to protect from the rain? And I assume you could still just set up a tarp overhead with paracord as a shelter (as well for cooking etc. while staying dry)? I imagine the entire setup would be pretty compact and light right?

crashdive123
01-12-2009, 07:46 PM
You can use them for protection against rain (tarp may be better) or bugs.

MCBushbaby
01-12-2009, 08:27 PM
The civilian bivouacs come with no-see-um mesh and plenty of headroom for reading while waiting for a storm to pass. But the MSS I have doesn't have either, so it's not my first choice during bug season. Instead I'll take my Contrail which has all the amenities of a tent and 1/2lb lighter (but more delicate and not freestanding). I see people tent camping in the winter but they think a tent is the means to being warm during the night. Not true. A tent only offers, maybe, 10F difference and you get most of that acting as a wind breaker. Winter tents are also heavier than the 3-season counterparts, take longer to set up, and aren't usually freestanding. But the bivvy is just unroll and tuck in for the night. I can also cook food while propped against a tree in my bivvy. Can't do that in a tent. But I camp alone so my pro-bivvy winter recommendation is bias. With a group of people I could definitely see the benefits of playing a game of cards in the tent.

Runs With Beer
01-12-2009, 08:41 PM
Iv never used a bivvy sack, But after reading your commets Ill have to give it a try, Where would be a place to start?

MCBushbaby
01-12-2009, 08:51 PM
Just get a big contractor garbage bag. It's water/wind-proof and should be a cheap solution to see how easy it is to winter camp without spending $200. Otherwise you can pick up the MSS bivvy on ebay for $40 (probably used but in decent condition).

Pict
01-12-2009, 08:59 PM
I have several of the low cost bivy sacks from the Sportsman's Guide (Guide Gear). I bought them as a low cost, entry level bivy to test the concept and I really love them. I haven't even considered upgrading yet. In fact I need to buy three more so I can take larger groups up into the mountains.

Paired with a poncho and either a tropical weight bag or poncho liner they work great fro the kind of minimalist survival camping I do. When I run trips into the mountains the entire shelter system consists of a bivy, tropical bag, poncho and paracord. We set up in natural rock shelters and use mountain grass for bedding. I have spent many nights in my cheap bivy in conditions ranging from dry season cold/wind, to mountain storms in rainy season, and even winter camping down to 18 degrees here in PA. In all of these conditions I have had ZERO condensation, and only a little water come in during a storm in the mountains when I had set up without overhead cover.

If you're looking for a good place to start I endorse this product. That's where I started and haven't been motivated to leave.

Don't sleep over an abrasive surface. Dry, clean, air them out them well. Often during a trip I will turn mine inside out and let it sit in the sun for a few minutes along with my bag. Great piece of kit. Mac

http://img254.imageshack.us/img254/4074/bb2leantocloseam8.jpg

Runs With Beer
01-12-2009, 09:02 PM
Thanks guys, Nice pic, Pict.

MANABA
01-12-2009, 09:37 PM
I have used the mss bivvy since it was tested and issued to the army. Honestly it was designed for troops that usually kept moving and not the stationary type. I never carried the interm. bag, I only carried the gortex shell(bivvy) and the green patrol bag due to weight, size, and ease of use in my ruck. Honestly I never even took the interm. bag out of the plastic. I did carry a poncho liner which I wrapped around my feet if it got extremely cold.(most of the time I had to leave my boots on) This is an excellent system but it is for simplicity and continuation of movement. Hence the name patrol bag. The compression bag also works well. I have used in direct rain of Germany and Bosnia. Not bad but not great either. I did get wet but not entirely soaked. Overall I would say this is a great system. Never tried any civilian models.:)

MCBushbaby
01-12-2009, 09:40 PM
How'd you get wet? Thru the zipper?

MANABA
01-12-2009, 09:51 PM
How'd you get wet? Thru the zipper?

Yes that and if you dont take care of the gortex shell it will seep through. I used mine for years and it was constantly abused then upon return from missions cleaned and washed. causing the gortex to fail sort of but my shell was probably 5 or 6 years old. Cant DX it until its completely unserviceable.:eek:

jbone
01-13-2009, 12:35 AM
pict- whats a tropical weight bag?

MCBushbaby
01-13-2009, 01:26 AM
Guess it's a water-resistant, synthetic fill sleeping bag rated to 50F

How close am I?

Pict
01-13-2009, 09:44 AM
pict- whats a tropical weight bag?

I don't have any photos (imagine that). My tropical weight bags are a little thicker than a poncho liner.

Brazil has night time temps that range from the low 70's/ high 60's in summer (if its raining) to the mid 40's/low 60's in the winter. There are times that the summer overnight lows will only fall into the 80's and it's still in the 90's at midnight (if it stops raining). Mountain temps in winter (dry, windy, cool) can get down to about freezing but rarely go below it unless you are on the major peaks (above 6000 feet). Lowlands in the winter can experience frost and I have encountered skim ice up around 7000 feet (Pico da Bandeira).

A standard 3 season bag for the US is overkill in Brazil for all but the dead of winter. A tropical weight bag is one that is comfort rated into the 50's or so, they are very light and compact. I have used a simple poncho liner in winter combined with a bivy and adequate clothes.

I did a winter trip before I left Brazil. I carried a pair of sweatpants, long sleeve T-shirt, fleece pullover, and a wool hat. This combined with my poncho liner, and bivy worked fine. I did have to keep a bed of coals out in front of my rock shelter to be able to sleep the night. Mac

Pict
01-13-2009, 10:02 AM
You wouldn't think hypothermia would be a problem in Brazil but it is a major consideration. In the dry season (winter) day time temps in the high 70's/low 80's will lull you into thinking that cold isn't a consideration. The night temps fall off like a desert in winter because it is so dry so depending on where you are you could easily experience a 30 to 40 degree drop overnight. Likewise in summer (rainy season) the rains moderate the heat. If it hasn't been raining it will be very hot, high 90's, for days on end. Then the rains come and you have day temps in the high 70's and overnight lows in the, soaking wet, low 60's. If you are damp in the low 60's with a slight breeze you will not sleep.

http://img147.imageshack.us/img147/3695/vayy056do8.jpg
This was a rainy season trip. These two guys spent the night under emergency, basic kit, conditions with only their machetes and poncho's for shelter. They had to dry out everything and keep a fire going all night in summer to stay warm.

http://img187.imageshack.us/img187/6585/rcmacsecandonacavernazn1.jpg
This was another summer trip with basic kit. We just had the clothes on our backs for this one, no fleece or sweats, so we had to sleep dry. Hot and soaking all day, miserably cold and clammy at night.

Mac

MANABA
01-13-2009, 10:12 AM
Ahhhhhh, the temps and weather there reminds me of home in the military.:D