Looking to get first bivy

Looking to pick up a bivy some time in the near future. I do quite a bit of hiking around Alaska and am looking for a lightweight shelter to carry as I frequently get quite a ways from my base camp.

The second purpose would be as a replacement to my tent on trips where I'm trying to cover a lot of miles fast. I'd be looking to use it for all 4 seasons so bug netting is a big plus. What do you guys recommend? I'm looking pretty hard at this model. http://www.rei.com/product/747832

Does the hoop make a big enough difference in ventilation and comfort to justify the extra weight? Comfort isn't a huge issue as I have no problems with tight spaces, but if the model with the hoop ventilates better and stays drier, it's worth the extra 10 ounces to me.

Look at the Integral Designs bivies. I have several bivies acquired over the years, and the ID one is by far the best overall. It does have netting, and yes, the hoop does make a difference in ventilation. One of the others I have is an OR, though not the same model as in the link. It definitely is not of the quality of the ID.

I've owned an ID Unishelter in eVent for about six years now and I am really happy with it. eVent fabric breathes really well and the pole only weighs about 4 ounces. The horseshoe shaped zipper makes it easy to get in and out of and the hoop provides ample interior space while keeping the fabric off your face (very important for comfort and livability). There is room for some gear and enough space for the loft of a winter bag. I have a 5x8 ID siltarp set up on treking poles to shelter my gear when it rains or snows. This has been used on week long trips and I have never gotten tired of sleeping in it.

These guys have it on sale right now:

http://www.prolitegear.com/integral_designs_event_unishelter_exp.html

I have always found Integral Designs' gear to be well designed and made of high quality material and workmanship. I guess that's why I own several of their products.

I have done a number of trips with just a bivy and found that in bad weather, you need at least a small tarp or something to cover you when you are getting in and out of the bivy. When it is raining hard, you will be suprised as to how much water will get into your stuff.

The best bivy with a hoop and a great ventalation system is made by ID. For light and fast, but no hoop go with Mountain Laurel Designs. They have some really light weight gear that is very well made. Plus they will work with you to customize your order. I have their Soul Bivy at 8oz with netting, it works great.

If you want something that does really well in bad weather, go for either Integral Designs eVENT Unishelter (highly breathable fabrics, a durable, bathtub floor, waterproof zippers, ventilation that can be opened in stormy weather, and livable space provided by an overhead pole, ~1.8 lbs) or Nemo Gogo (unique front entry and retractable vestibule option, ~1.9 lbs).

The Unishelter works great in summer too Black Diamond's Lightsabre is even better because the fabric is much more breathable.

As for the Alpine Bivy, it has plenty of great reviews so what could go wrong?

I have both the ID Unishelter in eVENT and the Big Agnes 3 Wire in eVENT. The latter is superior in every way. It deserves a look.

I do not get the attraction of a bivy. I thought I wanted one until I really thought about it. I do have a Bibler Winter Bivy but that is really just a water resistant bag for my down bag and nothing more.

There are a lot of one person tents that are close in weight, if not less in some cases, than a bivy. If I was doing a lot of climbing, maybe I could see it because of ease of set up, no wind load, etc., but for anything else, no way. I have spent a few days here and there pinned in my tent in the rain and would not want to have experienced that in a bivy. I'd rather have a small tent like a Hilleberg Akto, BD, or one of a lot of other tiny tents I've seen than be stuck in a bivy. Just my 2 cents. Maybe I'm missing something, but not sure what it would be.

As another ancient, battered, creaky geezer, I agree, as usual, with Bill and I have three I.D. bivies, one I.D. tent and an I.D. "shelter", my beloved Mega Sola. I have a lot of other I.D. gear, as well and am VERY happy with all of it. I would also recommend the eVENT Unishelter and a Silwing, Siltarp II or, my choice, STIII.

HOWEVER, the BA 3-wire, especially the new 2010 model IS very interesting and what I would probably now choose for ONE bivy for all my uses, if constrained to only one. It seems larger than the I.D. Uni., but, is LIGHTER....I wonder just how they pull this off?

Still, due to ease of setup under any conditions and utility as an emergency shelter if injured, I never go out without a bivy-tarp combo and have not for over 40 years. I prefer this to a tiny tent in most situations and my rigs are much lighter than my Hille. Soulo, which is my smallest tent....works for me.

Tom,

A bivy has 2 purposes. The first and most important is for some protection during a bivouac, just as the name says. This can be an emergency shelter that provides more protection during storm conditions than a tarp, or it can be for a planned bivouac when the route is known to require fast travel with an overnight rest point.

The second is much less important, and in my opinion, misused by a lot of ultralight backpackers, namely as a substitute for a tent. As you point out, there are a number of good 1 and 2 person tents that are only slightly heavier than a bivy plus tarp (even a SilTarp).

I do often carry an ID SilTarp for planned bivies with my ID bivy. Although this approaches the weight of my 1-person tent, it takes much less space than setting up the tent. It is hard to set a tent up for sitting on a ledge, for example, where you can get in the bivy, anchor in on a ledge, sitting on your pack for insulation, and use the SilTarp to provide some shelter for the stove, where you could not get the tent set up in the space available. Yes, you could use the tent as a bivy, but that means you carried the weight of the now-useless poles and pegs.

If you are trail-hiking, or even crosscountry, and will seek out places large enough to set up a tent, you might as well use a 1 or 2 person tent - it is a lot more comfortable and roomy. And the superlight version of the Megamid is only a couple pounds, with room to sleep 4 people. So for places where you can set it up, you might as well go for the roominess. Won't really work on a small ledge, though.