Borah Gear Cuben Bivy Review – Real-World Testing

After multiple multi-day hikes across Scotland’s notoriously wet terrain and a trip to the Dolomites that threw everything from intense sun to violent thunderstorms at me, I feel like I’ve finally put the Borah Gear Cuben Bivy through the kind of testing it deserves.

This isn’t a first-impressions review. This is a piece of gear that has earned its place in my pack—now three years in a row.

Ultralight MLD Tarp and Borah Gear Bivy

First Impressions & Build

The Borah Cuben Bivy is all about minimalism. Borah is a Montana based cottage company making ultralight shelter components such as tarps, bivys and groundsheets.

Built from Dyneema Composite Fabric (DCF), it immediately stands out for its incredibly low weight and clean, no-frills design. Saying that, I bought the bivy that I am using second hand, and the specifications aren't the lightest in the line up. I have all the extras here, with the side access zip (great when paired with side entry tarp) as well as the long and wide footprint. I probably would get rid of the long variant if I was to buy again, but I would keep the width for sure. Choice of materials here are great, and all the sewing is neat. After a few years of hard use I see no signs of wear or tear, of course being looked after carefully.

Performance in the Field

Scottish Rain & Boggy Ground

Scotland is where gear either proves itself or fails quickly. Persistent rain, saturated ground, and unpredictable wind make it an ideal testing ground.

The standout feature here is the bathtub floor and splash protection. Whether I was pitched on damp grass, uneven ground, or dealing with wind-driven rain, the bivy consistently kept ground moisture and splashback at bay. I never had issues with water ingress, even in less-than-ideal campsite selections - at least not at the fault of the bivy bag.

I would note here that I pair the underside of this bivy bag with the ULfoam mat in order to stop any punctures to the underside of the water proof layer of DCF flooring. I would advise adding something here as a ground sheet as the specs of DCF being used are very thin (which is what we want) but from experience will puncture fairly easily.

Thunderstorms in the Dolomites

I have had the pleasure of being completely soaked in this bivy in a few thunderstorms. The water came into the head of the bivy with wind driven rain, through the open end of my tarp door. This comes down to a poor choice of tarp and pitching for the weather conditions, not the bivy itself. However, One gripe here would be the footbox of the bivy when fully saturated gets very stuck to the quilt that I was using on the inside. To combat this I have sewn an extra chord tie out to the bottom of the bivy and attached it to the inside of my tarp. This means that if it does get soaked again, I will be slightly more comfortable.

Condensation & Moisture Management

I was sceptical after reading reviews of poor condensation management.

Paired with my Enlightened Equipment quilt, I experienced virtually no condensation or moisture issues, even in damp Scottish conditions. That’s something I’ve struggled with in other bivy setups.

Weight & Packability

This is one of the bivy’s strongest selling points.

It sits firmly in the ultralight category, and when you're counting grams on longer trips, it makes a noticeable difference. It packs down small, disappears into your kit, and doesn’t feel like a burden even on extended hikes with significant elevation. The DCF stuff sack supplied is a nice touch.

The long and wide variant I am using just now comes in at 150 grams. For the price, this is extremely competitive and within the lightest splash protective bivy bags on the market.

The Downsides

No piece of gear is perfect, and the biggest limitation here is space.

Even in the long/wide version, the interior feels tight. Once you're inside with a sleeping pad and quilt, there’s very little extra room to move. Compared to other bivy's in a similar weight class—particularly offerings like the Hyperlite Mountain Gear Splash Bivy—the Borah feels noticeably more restrictive. The big jump there in price though may make it worth this little niggle.

Who It’s For

The Borah Cuben Bivy is best suited for:

• Ultralight hikers who prioritize weight savings above all

• Minimalists comfortable with a snug sleep setup

• Users pairing it with a tarp rather than relying on it as standalone storm protection

Final Thoughts

After extensive use in some genuinely demanding environments, the Borah Gear Cuben Bivy has proven itself to be a highly capable ultralight shelter component.

Its strengths are clear:

• Exceptional weight savings

• Reliable splash and ground moisture protection

• Surprisingly effective condensation management (especially with the right quilt pairing)

I will be using it again this year on the Hebridean Way amongst other trips and look forward to many more nights on the trail!

Check out the Cuben Bivy by Borah here:

https://borahgear.com/cubenbivy.html