A traditional style of bivvy bag made largely from Gore-Tex Starlite – hence the price – the Mountain Equipment Borealis Bivi offers high levels of waterproofing and breathability in a compact package that can be washed (in pure soap) to keep its performance high. It’s pretty much even stevens on the weight and pack size stakes with the Rab Storm Bivi, featuring a zipped opening at chest level with a deep, draw-stringed hood to minimise moisture ingress. The central opening makes it feel less oppressive – previous models of the Borealis had a flexible window in the hood, though this has now gone – yet you can still seal it up against the elements pretty well. The Rab bivvy has an advantage in that it has no opening in the top panel and so naturally feels more protective in this area, though with the trade-off in feeling somewhat enclosed. It’s down to personal preference which of these you prefer. In terms of other features, the base is a robust nylon, all inner seams are taped, you get a double zip on the main opening for flexible venting, and the hood can be secured with Velcro tabs to the main body of the bivvy. Very simple, light and easy to pack – and even comes with a nice definition of the word ‘bivouac’ on the care label!
Top fabric Gore-Tex Starlite
Base fabric Hypalon-coated nylon
Packed size 29x12cm
The Mountain Equipment Borealis Bivi was the best bivvy in our test for extreme conditions.
Review by Simon Ingram
First published in Trail magazine September 2013