As the years rapidly pass by I’m starting to notice the old joints grumbling at the excessive weight of my rucksack. So as I need them to last a good few years yet, I’ve been looking at how to reduce the weight. Now while I still prefer the comfort of a larger tent on multiple day expeditions I’ve been experimenting with using Bivy bags for those single overnight stops. You know, the ones where its a day’s walk in to the foot of the peak, then a bivy, before completing the climb and walk out the next day. I’ve tried a few nights out with a goretex bivy bag with an open hood and although it performed well and felt very durable, I’m afraid the first night didn’t go well as I awoke with a start to find a slug crawling up my left nostril. So I started looking for a hooped bivy bag and finally opted for Integral designs cocoon bivy Integrals bivy is a single hoop design rather than a twin hoop like the Rab bivy, one of the mains reasons I went for the single hoop is its ability to be pitched easily on almost any terrain with minimal pegs in the ground, which isn’t always possible, once you get into double hoops and their associated guys lines then, well might as well buy a tent. On first examination out the bag the build quality seems very good with the Event 40D fabric having a robust feel about it, given its light weight.
Practice pitching in the garden provided no drama’s with it easily pitched in well under 5 mins (albeit in good ground), in fact its pretty much idiot proof. Out on the hill in the dark on the first nights test it was no harder to pitch, even though the wind was blowing, another advantage of a bivy over a tent. First nights test it was coldish and windy with clear sky’s, perfect bivy weather and according to the manufacturers the ideal conditions to test the Event fabrics breathability. Indeed the bivy performed very well on that account, time spent inside the bivy that night was aprox 10hrs, with the outer door completely sealed for most of that time. At no point was there any condensation build up on any of the inside surfaces, a very impressive result. outside air temp fell to +2 degrees C with the inside remaining at around 2 degrees warmer than the outside, normal for a tent. Wind remained around 15- 20mph for most of the night with a clear sky and low humidity (for the UK anyway)
One advantage this bivy has over its rivals is its extra length at 255cm (8′ 4″), this allows you to stow a lot of kit at the toe end, with being only 5′ 6″ and of stocky build I was able to store my boots and spare clothes along with a few other things ready for the next morning, rather than having to get outside in possible horrendous weather. One other advantage of doing this, is it form a bulge at the toe end and helps to lift a large portion of the upper fabric away from your sleeping bag thereby increasing overall breathability. The inside width of 80cm (23″) at the shoulders is also ample for someone of my stature allowing enough room for me to change clothes (albeit with some shuffling) inside the bivy, a major advantage on a wet day, having said this if you’re 6′ 6″ and built like a brick shithouse you might struggle. The second night was typical British November weather with strong winds, rain and high humidity with an outside temp of around +5-6 degrees C. In this high humidity and low temp Integral recommends that you vent the main door a little bit to aid breathability, but I tried it fully sealed anyway. On this occasion there was condensation forming on the roof on the bivy above my head in a little under an hour. So as per instructions I vented the top of the door just a fraction, this seemed to do the trick and the condensation soon disappeared and at no time did any rain enter under the storm flap. I had however on this time omitted to place kit on the inside at the toe well, in the morning I did notice that condensation had wet the outside of my sleeping bag where the fabric was in touch with the bivy bag. mind you nothing like as bad as rolling over in a tent and resting on the outer fly sheet, some gear at the toe end would help as described earlier. One disadvantage with a bivy is trying to cook your supper, at least with a tent you usually have a porch, with a bivy your relegated to outside. However with new technologies like Trekmates heatbox and perhaps even a jetboil (door vented), if you’re organised and small, you might get away with it.
Below are the specs from Integral Designs.
Area: 1.52 sqm / 16.36 sq ft, Width: 80 cm / 31.5 in (shoulders) , 40 cm /15.7 in (foot), Length: 255 cm / 100.4 in, Height: 60 cm / 23.6 in, Packed Size: 30 x 16 cm / 11.8 x 6.3 in, Packed Weight: 1033 g / 2 lbs 5 oz, Minimum Weight: 881 g / 1 lb 15 oz, Colors: Saffron, Olive
All in all I’m very impressed so far and give it a score of 4 out of 5. The only thing that lets it down is its price, at £250.00 its fu king expensive. However I did get mine for half price from Needle Sports so the bargains are out there.
Top Tips: 1) Slightly vent the door at the top in warm wet weather. 2) place your dry kit in at the toe end to raise some fabric off you’re sleeping bag and keep it dry. 3) if trying to pitch on rocky ground, stick your trekking poles/Ice axes through the loops at either end and place rocks on them, works a treat!