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Reviews > Shelters > Tarps and Bivys > Outdoor Research Advanced Bivy > Test Report by Jason Boyle

Outdoor Research Advanced Bivy

Test Series

Initial Report – November 20, 2008
Field Report - February 17, 2009
Long Term Report - May 18, 2009

Overlooking Women's Bay

Tester Information:
Name: Jason Boyle
Age: 31
Gender: Male
Height: 5' 6"/ 1.68 m
Weight: 180 lb/ 82 kg
Chest: 42"/ 107 cm
Neck: 16"/ 41 cm
Sleeve: 28"/ 71 cm (from the middle of my chest to my wrist)
Email address: c4jc "at" hotmail "dot" com
City, State, Country: Kodiak, Alaska, U. S.

Backpacking Background:
I have been camping and backpacking for about 20 years. My introduction to the outdoors started with the Boy Scouts of America and has continued as an adult. I have hiked all over the Southeastern, Northeastern, and Northwestern United States. I am generally a lightweight hiker, but will carry extras to keep me comfortable. I currently reside on Kodiak Island in Alaska home of some of the worst weather and most beautiful scenery around. I look forward to putting gear through the paces here on the Emerald Isle.

Product Information:
Manufacturer: Outdoor Research
Model: Advanced Bivy
Color: Blue Grey on top, Grey on bottom, bright white on the inside
Year of Manufacture: 2008
Listed weight: 39 oz/ 1106 g w/Pole
34 oz/ 964 g w/o Pole
Measured weight:
Total 38 oz/ 1077 g
Bivy and Stuff Sack 32.8 oz/930 g
Poles 5.2 oz/ 147 g
Length: 87”/ 221 cm
Peak Height: 20”/ 50 cm
Width at Shoulders: 26”/ 66 cm
Width at Feet: 19”/ 49 cm
Packed Size: 15 ¼” x 4” x 4”/ 39 x 10 x 10 cm
Pole Material: Delrin
Fabric: Gore-Tex® Respiration Positive™ on top
Hydroseal® coated waterproof nylon floor
MSRP: $289 US
Country of Manufacture: Made in China
bivy 1

bivy 2

Product Description:
A bivy sack in its most basic form is a cover that slides over a sleeping bag to protect it from the elements. The OR Advanced Bivy is more than just a basic sleeping bag cover! The bivy features two different fabrics. The top and sides of the bivy are made of GORE-TEX® Respiration Positive+ Fabric. This is a three layer fabric is supposed to be windproof and waterproof like other Gore Tex fabrics, but has been specifically designed to be more gas permeable for sleep systems. The fabric feels similar to other Gore Tex fabrics I have felt in jackets and pants. It is slightly crinkly but not too loud and the inside of this fabric has a softer backing material that is softer and quieter than the outside. The floor of the bivy is made of a Hydroseal® coated waterproof nylon. The outside of the floor has a smooth nylon finish and the inside of the floor feels rubbery. All of the seams on the bivy are completely covered with a tape to keep out the elements.

Bivy in fully open position

The inside of the bivy features two hook and loop pad straps. The ends of the pad straps are bar tacked in place and have an additional reinforcing fabric over the ends. The inside also features no-see-um mesh netting and a small mesh pocket that will hold items like a small flashlight or small cell phone. The outside of the bivy has a clean design with only a few unobtrusive logos. There is one small black tag that says Outdoor Research near the right pole sleeve and a small black Gore Tex logo on by the opposite pole sleeve. There are also reflective triangles with “OR” left out of the reflective tape on each side and a reflective word “Pole” at the end of each outside pole sleeve.

The “Delrin” poles consist of three pieces – a shock corded section, and two separate ends that slide over the end of the shock corded section. The separate ends have a male button on the end which snaps into the female snap sewn to the fabric of the bivy. One pole goes through a sleeve on the inside of the bivy and the other pole goes through a sleeve on the outside of the bivy. These two poles make a “living space” above the user’s head. The poles are optional if the weather is good or when using the bivy in an enclosed shelter. The bivy also has 5 stake out loops – 2 at the foot, 2 at the shoulder and 1 at the head of the bivy. It also has 3 guy line loops, but no line was included with the bivy for the guy out points. The foot of the bivy features a zippered; mesh filled opening to allow more ventilation to the bivy. The foot vent is also covered by a large storm flap. The main entrance to the bivy has a large two way zipper with pulls that is covered by a wire stiffened storm flap. The no-see-um netting has a small zipper with pull that allows it to be half way unzipped and laid flat when not in use. The bivy also has some lime green accent fabric around all the zippers. The bivy sack and poles came stored in a small stuff sack that appears to be made of the same material as the bottom of the bivy.

Reflective Triangle and small Gore Tex Logo

Initial Impressions:
The Advanced Bivy is exactly what I expected from reviewing the OR website, but I didn’t expect to be packed in such a small stuff sack. It was tightly rolled in a cylinder that wasn’t much larger than a water bottle. I removed it to explore the bivy’s features and found it difficult to roll the bivy and get it back in the included sack. I have also tried to stuff it back into the sack it came with and it was very challenging with the stiffened wire brim and didn’t really fit back into the sack very well or easily.

I am pleased that the weight of the bivy is even less than what OR states on their website. I am always surprised when something comes in lighter so I weighed everything multiple times using different methods and reached the same conclusion each time.

One thing that I have already found to be very annoying is the no-see-um netting zipper. It is a one way zipper meaning that the zipper pull doesn’t flip around the slider so that the zipper can be operated from either the inside or the outside of the mesh. The pull on the slider is currently configured so that it can only be unzipped from the inside, not the outside. The bivy arrived with the netting zipped closed. So when I was trying to set up the bivy for the first time on a freezing cold day here in Kodiak I couldn’t get the netting unzipped to put the pole through the inner sleeve. It probably took me 10 minutes to move the slider enough to get my full hand inside of the netting to unzip the mesh. This is an easily solved issue if OR used a zipper pull and slider that can be pulled in both directions instead of in only one direction or by not shipping the bivy with this mesh completely closed.

Hook and Loop sleeping pad straps

Except for the netting issue mentioned above set up is very easy. Unroll or unstuff bivy sack, stake down if necessary, assemble the two poles, slide in the inner pole first and snap the poles in the inner snaps, slide in the outer pole and snap it in place, guy out if necessary, that is all. At this point, the user has to decide how much or how little ventilation is needed since the bivy has four main configurations –full closed, storm vent, full vent, and open and pushed back (no poles). There is a warning on the inside of the bivy that says to leave at least six inches of the zipper open to prevent difficulty breathing or suffocation.

The care instructions for the bivy are pretty simple. It can be washed with powder detergent and allowed to drip dry or it can be wiped out with a sponge and allowed to dry. OR recommends making sure the bivy is completely dry before storing to keep mildew from growing on the fabric.

Field Report – February 17, 2009

So far I have been very pleased with the bivy. Set up is a snap, and with the exception of the netting zipper mentioned in my Initial Report all the zippers operate smoothly. I have experienced a bit of condensation inside the bivy but it wasn’t as bad as expected. It has shed light wind, a dusting of snow, and outside condensation with no problem and durability seems good at this point.

Field Conditions:
I have used the bivy on two overnight backpacking trips. The first trip was to Termination Point and the temperatures were between 20 F and 32 F (- 7 C to 0 C) with winds between 10 to 15 mph (16 to 24 kmph) and a light dusting of snow overnight. The bivy was used in conjunction with a tarp set up in a “Baker’s tent” configuration and no groundcloth underneath. The second trip was to an unnamed point overlooking Pillar Beach. Temperatures were between 10 F and 14 F (-12 C to -10 C) with winds up to 20 mph (32 kmph) and off and on snow showers. The bivy was used inside of a double wall four season tent. Both nights, I used the bivy with a 20 F (-7 C) synthetic sleeping bag.

After two nights of use with the bivy, I am pleased with the performance so far. I evaluated the bivy on three aspects – usefulness, breathability, and durability. I think the bivy is very useful and allows me a lot more flexibility in choosing a shelter for my backpacking trips. For my Termination Point overnight, I knew there might be some scattered snow showers and wind, but that overall it was going to be a fairly mild night weather wise in Kodiak, so I decided to use the bivy in conjunction with a tarp. Set up was a breeze even though I reached camp after dark; I picked a flat spot between a couple of trees overlooking Narrow Strait. I was able to quickly slide in the two poles, set the stakes and I was done. I then put a tarp over the bivy in a “Baker’s tent” configuration with the back wall towards the windward side. I was able to easily fit my Exped Downmat 9 pad and synthetic sleeping bag inside of the bivy sack leaving plenty of room for assorted small gear like gloves, jacket, water bottle, and bear spray at the head of the bivy. Even with the back wall of the tarp blocking the wind I could still feel some getting under the tarp. Since I had the bivy completely unzipped, I zipped the top of the bivy about a quarter closed blocking off the wind from that side. I was amazed how much room I actually had with the bivy zipped up. It wasn’t a ton, but I was able to read a magazine while lying on my back with little problem. Though I wasn’t fully exposed to the snow on this trip, the foot of the bivy did get covered with snow. Nothing leaked through and the snow was easy to shake off while I was packing up.

On my second trip, I used the bivy without the poles inside of a two man tent I was sharing with a hiking partner. I used the same sleeping bag and pad configuration as before, but it was much colder and windier this trip, and we kept the vents on the tent open to cut down on condensation inside the tent. Even so, I was completely warm inside the bivy and sleeping bag. I can’t quantify how much additional warmth it adds, but based on my experience so far, I would currently feel comfortable taking the bivy and my synthetic bag down to single digits. During both trips, I felt like I had plenty of room to toss and turn inside of the bivy and never felt claustrophobic. I also found that there was room on the sides to put additional clothes and such, but not as much room as at the head of the bivy. My only real complaint about usefulness is the stuff sack that came with the bivy. It is a challenge to make the bivy fit back in this sack. I have switched to using a larger sil nylon sack which allows me to easily stuff the bivy.

My biggest concern with the bivy was how breathable would the material be? And so far the breathability has been ok. During the night where I slept with the bivy about a quarter closed, I had some condensation on the hood portion above my head and some a little bit further down inside of the bivy. I expected the condensation above my head but not further down inside the bivy. I had hiked pretty hard trying to get to camp before dark and worked up a good sweat so my guess is that damp clothing between my bag and bivy caused the condensation in that part of the bag. Overall it wasn’t very much condensation and was easily shaken out. The second trip inside the tent, I didn’t have any condensation inside the bivy. It was a leisurely hike which didn’t generate much condensation and the bivy was mostly open since I was in a tent. I think I could deal with my clothing causing condensation by using a vapor barrier liner inside my sleeping bag. The condensation hasn’t been excessive and I am purposefully using a synthetic bag in case something happens and my bag happens to get wet. I will continue to monitor condensation throughout the test.

My final concern was with durability. The bivy doesn’t feel flimsy, but I don’t want to poke a hole in it either. That being said I used it without a groundcloth at Termination Point. I cleared the larger sticks and pine cones from my spot and that was it. I was on higher ground so the ground was fairly dry. After sleeping there for a night there were no issues. I wiped off a few smaller sticks that had stuck the bottom and stuffed it into a stuff sack. I haven’t noticed any wear with the zippers, or interior of the bivy, yet but will continue to monitor this over the next two months.

Long Term Report – May 17, 2009

Sunset at Uganik Lake

I have continued to be pleased with the performance of the bivy, though unfortunately I have not experienced any really challenging weather other than some snow. Set up is a breeze, I find a flat spot and unroll the bivy and based on the weather, I either use the poles or don’t. Even after using it the bag in snow, grass, and rocks, it still looks new. The breathability has only been ok; I have had significant condensation with the bivy hood mostly closed. My only complaint is the bug netting zipper, which is challenging to open from outside of the bivy.

Field Conditions:
I have used the bivy on two trips since my Field Report; a two-night snow shelter building trip on the flanks of Pyramid Mountain, and for two nights during a bear hunting trip to Uganik Lake on a remote part of Kodiak Island. Temperatures for both trips were in the 20’s F (-5 C) at night. The winds on Pyramid were quite strong blowing 45 to 50 mph (72 to 81 kmph). The winds at Uganik Lake were steady 15 to 25 mph (24 to 40 kmph). I didn’t experience any precipitation on either trip, but did experience bluebird skies, a rarity here on the island. Elevation at Pyramid was around 1400 feet (427 m) above sea level while at Uganik Lake I was at 75 feet (23 m) above sea level. I used a synthetic 20 F (-7 C) bag during my Pyramid Mountain trip, and a 20 F (-7 C) rated down quilt on my trip to Uganik Lake.

Set up is a snap

Like I mentioned in my Field Report I evaluated the bivy on three criterion – Usefulness, Breathability, and Durability. I was able to use the bivy in a couple of different configurations over the past couple of months. For my trip to Pyramid Mountain, I used the bivy without poles in a tent the first night, and then I spent my second day digging a small snow cave where I spent the night also using the bivy without the poles. At Uganik Lake, I used the bivy in the “Storm Vent and Fully Closed” configurations in a small clearing near the lake edge. Even though temperatures with wind chill were in the single digits on all my trips, I was able to use a 20 F (-7 C) sleeping bag. The bivy provided a bit of extra protection to help me stay warm even in temperatures below the rating of my sleeping bag. As I mentioned previously, there is ample space in the hood for me to read a magazine and store a few necessities such as a headlamp, some spare clothing, and my 44 magnum. One area I was concerned about was how the bivy would perform in my snow cave. I spent the majority of my time helping scouts from my local Boy Scout troop dig their caves so when it came time to dig mine I made a fairly small cave where the bivy would be touching the walls on all four sides except for where my head was at. I am pleased to say that I didn’t have any snow penetrate the top, bottom or sides of the bivy. Though I didn’t have the opportunity to use it in the rain, I am confident that the fabric will keep out the rain, but would potentially lead to another issue which brings me to my next criterion – Breathability.

Settling into my Snow Cave

Breathability was only ok with the bivy. Since I expected condensation to be an issue, I was very careful to make sure I slept in “sleep clothes” to ensure I wasn’t bringing in sweat laden clothes which would have caused excess condensation as they were dried by body heat overnight. When I was able to use the bivy in the open configuration or with the hood mostly unzipped, I had just a little condensation. If I had the hood mostly closed, I ended up with quite a bit of condensation in the hood. In all configurations, I ended up with a bit of condensation on the mid body portion of my sleeping bag, however the amount of condensation was more significant when I had the hood portion zipped mostly closed. I did use the foot vent in all conditions, but it didn’t seem to make any significant difference. To me this is one of the trade offs with using a bivy sack and why I like to use a tarp if possible when I am using a bivy. A tarp allows me to keep the bivy as open as possible but when coupled with a closed bivy gives me solid protection in case the weather goes south. I didn’t really get to experience any bad weather this time, but I have in the past and used this technique successfully.

My final criterion was durability. The bivy still looks brand new even though it has been used on snow, grass, rocks, and tent floors. I haven’t even managed to scuff the bright white interior of the bivy yet. Though I haven’t had any durability issues, there is one area that I am concerned about – the poles. Not that they will break, but that I might lose the end poles that connect the poles to the bivy. While preparing for my trip to Uganik Lake, I had a moment of panic when I couldn’t find the end poles… but eventually I did. One improvement I would like to see would be the connections built into the poles so there would be one less piece for me to keep up with.

Frosty Morning

In conclusion, the OR Advanced Bivy is a well built bivy that provides good room and weather protection, but like any other bivy has some condensation issues and several pieces that I find easy to lose. This concludes my Long Term Report. Thanks to and Outdoor Research for allowing me to participate in this test.

Read more reviews of Outdoor Research gear
Read more gear reviews by Jason Boyle

Reviews > Shelters > Tarps and Bivys > Outdoor Research Advanced Bivy > Test Report by Jason Boyle

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