Seal line boundary pack dry bag blue the legendary boundary pack is perfect for everything from canoeing and canyoneering to protecting your gear on trains buses and burros it features our watertight dry seal tm roll top closure along with a heavy duty 30 ounce scrim reinforced vinyl bottom and 19 ounce scrim reinforced vinyl body a lightweight suspension system includes waterproof and ventilated shoulder straps as well as a waist belt on every size available in three sizes the 1