The kind of thing that only covers your head/chest. I can see the obvious advantages of low weight, small footprint, etc but I'm more concerned with how well a bivvy bag will breath once sodden if it's raining.

Anyone?

Tried this twice a few years ago-



On the first night I though it was amazing, the best solution ever. Good views, light, tiny packsize, easy to pitch, uber cheap.

Then on the 2nd outing it rained. I had exactly the issue of your concern - condensation. It rained pretty much all night and the condensation build up was shocking, even with only the lower half of the bag being exposed. With no breeze to aid transpiration (?) and a sodden fabric it just couldn't breath enough and it was a pretty uncomfortable night. It's since been in the bottom on the Bivvy box. It also offers nowhere to get changed out of wet kit.

i have one based on the backpacking lite design.

http://www.backpacking-lite.co.uk/diy/m ... -tarp.html

only used it a couple of times - last time out was the wettest night all year and i really struggled in the morning - apart from waking up with a personal moat i found it really difficult to stay clean and dry whilst changing packing. and put it away not to be seen again.

having said that i found myself just as wet on the second night of the WRT with my much bigger tarp, so.... the micro tarp is coming back out on friday for a trial run.

I will bring it to BB200 if you want a look.

reading my reply i never mentioned the bivvy! i find no difference with my hunka weather it is wetted out or not. always sweaty on the inside!

always sweaty on the inside!

Do you find it's worse towards the foot end of the bivvy bag Thom?

to be honest i've never checked in detail - i normally notice the bit closest to the opening.

do you mean with the hunka or under the micro tarp? I will be using it on friday. I will post up some results on saturday. :)

If you have drawn up the opening to keep snug, then breathing into the bivvy-bag can create a huge amount of condensation near the top end.

I'm suprised by how little condensation I have had in the TN Moonlite this year.

I'm suprised by how little condensation I have had in the TN Moonlite this year.

Me too, it's been a nice surprise

ditto. 3/3