Although Terra Nova are confident that Terra Nova's Waterbloc material will outperform any similar groundsheet fabric, the Terra Nova Cosmos Groundsheet Protector offers some extra protection against sharp objects as well as keeping the tent underside clean.
Terra Nova groundsheet protectors are sized to fit exactly under the inner tent, and attach to the tent pole feet with shockcord loops to keep them in place. This ensures the weight penalty is kept to a minimum on our lightweight models and our expedition tents gain the extra durability they need for the conditions they're used in.
