DNS Alpha exhibited with Mountain Horse Solutions which is a division of Global Ordnance. In addition to their clothing systems, they showed us their Vapor Barrier Sock system which was recently adopted by a NATO SOF unit.
It comes in 6 sizes with the VBL made from silicon treated 30D nylon and fully taped. The liner sock is manufactured by CEP from Merino wool.
What is the difference between a vapor barrier sock system and the Goretex socks you can put on over your socks?
A goretex sock is just that- goretex. It is “breathable” and moisture leaves the inside. A vapour barrier is completely impermeable to moisture- is is fully water vapour proof. Basically putting a sandwich bag over your foot. While this might seem crazy, it is actually very important in cold and extreme cold weather environments. At significantly below freezing, your boots still end up wet- but not from the outside- from your own perspiration. A vapour barrier sock keeps you from sweating into your boots and ruining the insulation value when they are wet. At -40 your boots are basically waterproof anyway due to everything outside them being frozen- the vapour barrier stops them from getting wet at all by stopping your sweat from soaking into the lining.