Sea To Summit Ultra-Sil Dry Bag

The Sea to Summit Ultra-Sil Dry Bag is a roll-top dry bag built from 30D Ultra-Sil CORDURA nylon with a PU coating rated to a 2,000 mm hydrostatic head — enough to keep contents dry in a pack under normal rain and splash exposure, though not the fully submersible level of Sea to Summit's higher-end eVent bags. This particular size holds 8 L and weighs 39 g, sitting mid-range in a lineup that runs from 3 to 35 L and 30 to 74 g. The roll-top closure with a buckle and taped seams is the standard formula for lightweight dry bags: reliable water resistance for the weight, though it demands a proper three-plus roll and firm buckle closure to seal fully, unlike a zip-based waterproof bag. At under 40 g, it is a practical way to isolate a sleeping bag, spare clothing or electronics inside a backpack without committing to a full waterproof pack liner, and its light weight makes it easy to carry two or three sizes for organizing gear by category.