Outdoor Research Interstellar Bivy

I like this bivy a lot. super lightweight and super breathable. perfect.

Great concept and design. High-quality materials and zippers. The major downfall is that it is simply too narrow. If you keep your sleeping pad outside of it it adds a little room, but then you probably need a ground cloth for that- thus defeating the purpose of the lightweight/waterproof bivy. I'm 6'1" 195. make an XL version with more girth and this would be perfect.

When you opt for a Bivy you sacrifice comfort for weight and space. That is a given. So here are the pros and cons acknowledging, that if you're claustrophobic, a bivy is not going to be comfortable. That said, you should also consider whether you should just have a one person tent for a pound extra and five more minutes of set up time. In exchange you get more headroom, more loft for your sleeping bag, and a small vestibule. The extra space of a tent may be well worth the weight. While the tent will probably only be a three season, the advantage of the Bivy low wind profile and weight, and simplicity. Read on for pros and cons:Tight, particularly near the footbox: The space in this is a bit tight for four season gear. You cannot include 3" inflatable pad here, so you have to opt for the foam variety or things just won't fit. Even so, a standard 20" foam pad, is a bit snug. I ended up using a standard thermarest foam light pad, which works. FYI, I'm 5'7" and 140 lbs, so if you're over 6'3" I would assume it is SNUG.Complicated zippers: The next thing is the zippers. There are A LOT of zippers. To be specific, there are SIX for the interior bug net (two for the head, two for the left arm, two for the right arm), and SIX for the exterior Bivy (two for the head, two for the left arm, two for the right arm). At first this can be pretty intimidating. However, it is a bit more manageable once you realize what they are all there for. OR should have COLOR CODED the zippers, and this is a major design flaw. Also the bug net zippers look the same as the exterior zippers, so at times, it can feel like you are staring at a seas of zippers. They do have little pictures on them, but COLORS and PICTURES would have been much better.Zippers can make setup complex: one of the advantages of a bivy is supposed to be easy setup, but with all the zips, you have to get them oriented before you can start using it, which slows set up down.Two stake points: I guess they would prefer that you use guy lines, but it has just two stake loops, and the one by the head is not at ground level, which is awkward without a guy line.Pros:Top loading: That said, once inside the Bivy is livable, and I liked the top loading design. You can sit up easily without taking the thing apart, which is nice.Lots of options: The idea is that you can stay in the BIvy and cook or read while you're in there. This seems a bit overdone, but with time, I think that I could like the zippers, particularly for the ventilation. Using this model, you can vent in three places, which is unusual for a Bivy.Breathable fabric: fabric minimizes condensation and stays dry.WETNESSI tested it in a storm with heavy downpours and where we got over an inch of rain in about 6 hours and NO TARP. It is not 100% waterproof in those conditions. Surprisingly, it "wetted out" near the footbox, leaving the sleeping bag mildly damp there. Considering the monsoon, I would say it was passable, but not exactly what I was hoping for. If you are going to be in HEAVY rain, I would recommend bringing a garbage bag along to prevent this. A bit hard to believe given how fancy the material is. Perhaps this is because of the pooling at the top of the bivy, as I was not in the bivy the entire storm, but dipped in after about 5 hours, to see how it was performing. I would say, better in SNOW than HEAVY RAIN, but passable. I am not sure if this is due to how wet the air was and whether there was condensation inside, but the takeaway is that it does get mildly wet. So, if you think it will be a torrential downpour, plan accordingly. Fine in a pinch, but not was waterproof as I would have hoped. Otherwise, as a top loader, it was fairly simple to get in and out without getting massively wet, but your sleeping bag will get a bit wet.In the snow, it stays dry. I tried it in the snow, and it did not let moisture in.Conclusion: If you're not a huge person, it is decent, albeit expensive. I like the top loading design, although the zippers are a bit much, but probably do increase the livability if you are in this for a few nights. You can completely engineer around this to make it simple to get into and exit, particuarly without the bug net. If you plan to use it for four season performance, note that it is not 100% waterproof and will "wet out" just like a raincoat in MAJOR RAIN. In that case, you may sacrifice the breathability for the performance of the ALPINE instead. Otherwise, it seems like a nice piece of gear. If you can have BOTH, that might work, but as other reviews have said, I would say, think about how you are going to use it. If you think you will be the rain from time to time, this probably works with a synthetic bag, and an interior plastic bag (trash bag) at the foot. If you think that you are definitely in for a MAJOR STORM, then, consider something like the ALPINE instead or BRING A TARP. FYI, it dries relatively quickly once the storm is over.