The same sails that withstand whipping gales at sea make this pack virtually indestructible. The Drop Liner uses repurposed boat sails that would otherwise go to the landfill to create a waterproof, 600-denier nylon packbag that we couldn’t even scuff. “After two months of dragging the pack across rocks and scraping through overgrown bushes on hikes in Washington’s Cascades, the material hasn’t suffered at all,” one tester says. Amply padded shoulder straps and a rigid polyester backpanel allowed her to carry 20 pounds comfortably. Bummer: Price is steep for a pack of this volume.