Mystery of the Wet Butt

**jbphilly** · 04-29-2011, 16:34

...pretty much what the title says. The last few nights of the Israel National Trail, it was kind of hovering on the verge of summer (it's freak weather though - it should NOT still be raining in late April! Nobody's complaining about extra water though) which means humidity is on the rise and soon it'll be too hot to live, much less hike. Glad I'm heading home...

Anyhow, I think that humidity might be connected to the fact that I would wake up in the morning and notice the bottom of my sleeping bag, right around the butt area, was somewhat damp on the outside. Not very wet, but damp. It's a synthetic bag anyway and I never felt a thing, but if it were down it could have been a problem.

I'm in a Grand Trunk UL Skeeter Beeter, North Face Cat's Meow 20F bag, thin Altus sleeping mat for insulation, and when it looks like rain or wind, some cheap no-name but fairly light tarp hung up. The first night I noticed this I had the tarp up and it drizzled some in the morning, so I figured maybe the rain got in. But everything else was dry. The only way I could see rain having snuck in was by dripping down the suspension ropes, but I'd think it would have gotten caught at the S-hooks and fallen off.

So my best guess is condensation of some kind. Anybody have theories/explanations? Also, if I were to switch to down, which I plan on once I have the money since I want to cut down weight - is this kind of dampness the kind of thing that would cause problems for down?

**DuctTape** · 04-29-2011, 17:17

Condensation of your perspiration on your sleeping map which traveled to the lowest point, under your butt.

**turnerminator** · 04-29-2011, 17:34

I find that I only get dampness when I get in the sleeping bag and especially with synthetic. Using a bag as a top quilt keeps things much dryer for me, even in a non breathable hammock.