Does anyone know a lightweight bivybag for two persons? I got the heavy nylon coated one, but that one is big and heavy. I also got a two AMK heatsheets bivy's, but they are just for one person.

It is just for emergency's so it doesn't have to last more than a few days. Weight and size is a big issue for me.

Oware makes a two person bivy. I have no experience with it, but I assume it's like all other bivy's, just bigger. Weight and size aren't unreasonable, can't say the same about cost.

http://www.owareusa.com/

How about one of those lightweight Tube tents from campmor.com or the Large orange trashbags from bepreparedtosurvive.com.I have 2 of the trashbags,they are bright orange,aprox.60"x30"x4mil.thick or possibly a Dutch Military Poncho from Sportsmans Guide

I will be using it for mountainering, so a tube tent or poncho is not a option. I want a really small, affordable two person bivybag. The lack of extra clothing and sleeping bags, means keeping each other warm is importent.

The Oware one looks ok, but the price is a bit to high.

No Kidding on this one,How about a Military Body bag?They are usually as tough as nails,Rip-stop waterproof Nylon with Very Heavy-Duty Zippers,Some even come with Strap handles,of which you could incorporate in your rigging,so as to sleep suspended if you had to,& They come in many different sizes as well,& The Best part,Very Affordable!Just don't eat any Beans,otherwise the intended use of such may fall to it's primary purpose,lol! Throw in a Lightweight Poncho liner,& I'd think you&yours will be Well off!

A while ago I found this Ortovox Gemini Double Emergency Shelter, but I think one person might have a hard time breathing... But maybe that's not the right picture, because the single person one looks the same.

Edit:
Oops, first post and already made a fool out of myself: You can put your head through the hole and use it as a poncho, but there's a big opening at the "bottom", so both people can breathe.

Please correct me if I am wrong here, but I read your comment as the bivvy bag would be a substitute for warm clothes and sleeping bags??

The bivvy bag is an emergency option, not a substitute for clothes and sleeping bags. The bivvy bag is, as you probably know, not insulated.

The bivvy-bag ( a "windbag", "vindsäck" in swedish, "vindsekk" in norwegian) is almost a compulsory item when travelling the mountains of the north here, (Sweden, Norway and Finland) during all seasons.

Over here there is quite a range of different bags but I still prefere the brittish ones;
I own and use this one, check this out:
http://www.outdoordesigns.co.uk/products_shelter_group.html

Being new to the UK, I see these 'botty bags' being sold over the place. I have never saw them before still a few months ago.

Does anyone have any experience with them?

Kris

I'm intrigued about the wind bag concept too - we are not the Arctic north by any means, but there's enough went and windy weather arouhnd here in the PNW even in the summer that I sometimes long for a better shelter than a jury-rigged tarp. Bork^3, do folks pack these botty bags and deploy them only in emergencies, or do they also put them out during breaks in hiking etc? Would you use such a bag for overnight camping, or is there inadequate air circulation for that (except in an emergency?)

Not all people pack these bags, they are not a compulsory item, only recommended.
The "windbag" is definetely not for emergency situations only. They are very commonly used when taking a short break during hiking as well, especially in winter.

The bags are used in any situation when you need to get away from the elements, e.g. hard winds when no natural cover exists and a tent would perhaps be too difficult to set up or if you didn't bring one! Perhaps you are wet and need to change your clothes or need to tend to your injured or sore feet and the rain is pooring down, then the windbag is a great piece of kit.

The bag is quite versatile, you can set it up as windscreen, you can sit on it, use it as a groundcover for your tent or sleeping bag, use it as a signaling device, waving it about to attract attention.

People do generally not use it as an overnight camping option, unless it is a more extreme situation but in calm weather I cannot see any reason not to, the ventilation is more than adequate for it. The bag however isn't "tent-shaped" and do not provide the same amount of room as a tent would.

During a ski patrol about 16 years ago, it came very handy indeed. I, and another guy, were on our way to a cabin in a remote region of northern Sweden and a storm was on its way, but we had to go, (this was during my military service). The snowstorm was over us quite fast and I decided early that we had to dig in (make a snow pit) and sit out the storm in the windbag. Sitting on our backpacks eating canned food, packets of butter and chocolate we endured 27 hours before we could move on. The bag helped keep us snug and since then I never hike in the north without one.