Old school diehards of water-resistant (but not waterproof) bivy sacks know that Backpacking Light and Oware USA collaborated to introduce this concept to the backpacking community nearly two decades ago. A water-resistant, highly breathable bivy sack could shed wind, rain mist, condensation, and spindrift while sleeping under a tarp or pyramid without creating extreme condensation. Since then, there have been lots of copies but the Katabatic Gear Bristlecone is one of our favorites. It offers tie-up points at both the head and foot and this allows for full-length ventilation along the length of the sleeping bag. Easy entry/exit and quality materials round out this recommended bivy sack.