I currently own a Big Agnes Lost Ranger 15 bag, and it is the previous version, not the new one with water-repellent down.

I am getting ready to leave on an 11 month backpacking trip to 11 different countries. I am nervous about my sleeping bag in some of the countries in Africa and South Asia. Instead of forking out the $300 for a new water-repellent down bag, is there another option? Can I sleep in my sleeping bag also inside a waterproof bivy sack? Does anyone have experience dealing with down bags in humid and wet conditions?

Any help would be greatly appreciated!

Howdy, and welcome.

Two-part problem: storing it in a way it stays dry in very wet conditions and drying out your own perspiration it inevitably picks up while you're using it.

The first bit is easily achieved using a dry bag stuffsack and pack raincover, the second is tougher. You need to air the bag out, either in the morning or that evening before going to bed, otherwise moisture accumulates with time, flattening the bag until it's pretty useless and you're forced to drop everything to get it dry. (I'm envisioning monsoon season somewhere.)

So I guess the answer is: depends. Mostly depends on whether you'll have to opportunity it dry it out avery few days, if not daily. If not, then I'd use something else.

Waterproofed down is so new I don't know anything about its performance over the long haul. A good synthetic bag will be plenty warm but bulky and heavy, compared to down.

Good luck!

A waterproof, or even a Durable Water Repellant, bivy sack will just trap more moisture inside. Your body puts out a considerable amount of moisture ("insensible perspiration") during the night. Normally your body heat shoves it out through the shell of the bag. Adding an extra waterproof layer just means that body moisture will condense on it.

For traveling in tropical countries, I wouldn't take a down sleeping bag anyway. What about a 40* synthetic quilt? Even that will be too warm most of the time. Check with Mountain Laurel Designs or Enlightened Equipment for possibilities.

Since this site is about wilderness trekking, not budget travel, you might find more help on a travel site such as Lonely Planet.

When airing/drying your sleeping bag have the black side (if you have...) towards the sun.

Thank you so much for your response! I really appreciate it.

What is the best way to dry it out? I believe that I won't have to pack up my gear every morning. I will be able to leave my tent and everything out for a month at a time. Meaning that I won't be required to stuff my sleeping bag into it's stuff sack every morning.

you can try the Snugpak Jungle bag. It's rated for comfort to 40*, and can be had on ebay for anywhere from $70 - $90. I think they're on Amazon as well. I'vwe got one and have used it for about 3 seasons here in Texas and whether it was hot and dry or hot and humid it performed well. It's also fairly light weight and compresses really small