Sierra Designs Didean Bivy - Waterproof

I used it this weekend in Hell's Canyon during heavy rain. i went to bed damp and woke wet. Too much condensation, and no evidence of breathing.

I use this bivy as my main form of shelter on trips. The bag is long with extra length (over my 6' body) to hold my boots, headlight, phone and assorted clothing items. The bag is plenty wide for the above items, my mummy bag and a wide EMS sleeping pad. I used it in a light rain twice and the second time the foot box of my sleeping bag got wet...not just condensation. Later, I used Kiwi waterproofing spray and slept in a steady drizzle and the entire bag was dry. I am now happy with the bivy and how easy it is to use in thick woods where a tent would never fit. The way I use this bag helps keep me dry. I put a poncho on the ground to protect the bag from general grime and wetness. I then sleep with the bivy completely zipped except for about 4" for my nose and mouth to "stick out". If it is raining I modify the opening so that the lower portion of the opening is under the side of my face and the upper part sort of hangs over the top side of my face creating a little "porch" for my face and preventing rain from hitting my face. If it really comes down (rain,) I just back my head from the opening a bit. Using this method I only get very slight inside condensation in humid weather and I can "pump" the bag open and closed with my legs to get fresh air into the bivy if needed. Using the bivy in this way makes set up and decamp very fast, which is necessary to stay dry when it is raining.

From the once-over in the livingroom... nice, well made piece that will fit into multiple sleeping systems. Smaller/lighter than my old bivy sack.

Used product and enjoyed lightweight packing but did collect beads of h2o minimal however did make bag damp. Good buy for value.

Lightweight and waterproof. Not a replacement for a tent, but it allows you to sack out anywhere in nearly all conditions, provided you have the appropriate sack.

I use this product for backpacking when every ounce is scrutinized. pack size and weight are exceptional. like all bivys when you breathe in them they hold the moisture. It dries well and quickly. If you want something that breathes better get a tent and deal with the extra weight.

Nice bivy. Seems very breathable, there's a mesh panel over the facial area, so usable when warm and mosquitoes present.

Nice Product for the weight. Does what it is supposed to do. Remember this is not intended to replace a tent! It is a bivy....that is what it is for and it does just fine.

Perfect if you like to travel light.