Lightest WPB Bivy Bag

Tom,   It will be interesting to see what shows up here.  A year or so ago 4 of us went up to climb The Moose, a local bump in the Olympics.  We set up a camp the first night, a bivy on a high ridge.  It blew all night and I had my old Gortex bivy bag and did fine.  My friends all had lightweight bivy bags and agreed that they didn’t work well in the wind; that mine was a better arrangement.  So I suppose it depends on the amount of exposure you expect.

I have and use the Borah Gear Snowyside E vent bivy. I have used it plenty of times and in winter exposed in heavy storm. Unfortunately they do not sell them anymore. I am glad that I purchased 2 of them when they were available.  Sorry I can’t answer your question. I don’t think its the lightest bivy out there, but I do know it works well and I am happy with it.

One of the lightest is the MSR Pro Bivy at 10 oz.

Otherwise I think you’re looking at the MLD event bivy, or some UK and European brands.

I picked up the MSR last year and like that it doesn’t zip up. But my bag is also zipperless and I used it in the winter. So no bugs to contend with.

I think the MSR Pro Bivy is the lightest option right now. Then the MLD eVent bivy and the Outdoor Research Helium bivy. The Miles Gear Pico bivy is heavier, but another option too. Locus Gear used to make their Pneuma eVent bivy, but I don’t see it on their website anymore. They might build one as a custom option.

Thanks for the input, guys.  Now I’ve got some beta to work from.

I’ve had the MLD eVent bivy for getting on close to ten years now.  I’ll occasionally take it as a stand alone shelter- it breathes decently (as decent as can be expected for full waterproofness).  It definitely cuts the wind well and does add some warmth to your sleep system.  At 12 oz, it’s pretty light.  Now that I own a 17 oz shelter that has full bug netting, a bathtub floor, room to sit up and a good sized vestibule, it goes a lot less often :)

I do however use it more in the winter though with snow shelters.  No substitute for that scenario.

Thanks, Mike.  I have a Z-Packs Sol Plex that weighs ~17 oz with stakes, and was hoping to find a bare bones solution with a side zip somewhere around 8 oz for a very specific purpose.  From what I’m seeing here, it’s looking like I will stick with my tent.  The minimal weight saving just doesn’t justify all the downsides of a bivy for three season situations.

I’ve been using the Montbell Breeze Dry-Tec WPB Sleeping Bag Cover in size Long/Wide for years and I find it functions quite well. Weighs 8.3 oz, however the Regular is 6.3 oz and the Regular/Wide weighs 7.6 oz. The Long/Wide is VERY roomy and will accommodate a 20 degree bag with someone under say 200 lbs. Problem with many sleeping bag covers is that they’re too restrictive. https://www.montbell.us/products/disp.php?cat_id=14007&p_id=1121328