Paxson: "The 60-Liter version of SealLine's Storm Sack is described on different sites as either a light dry bag or a heavy-duty pack liner. During the 245-mile packrafting portion of Expedition Arguk, I used the SealLine Storm Sack as a liner inside my Osprey Aether 70 pack, which was strapped to the bow of my boat and constantly sprayed by paddle strokes, waves, and rain. Because it has no automatic valves or air-permeable fabrics, the Storm Sack also did (completely unapproved) double-duty as a backup flotation device in case the raft lost air. While its job is a bit mundane (big waterproof bag--got it) it's nonetheless critical, since nothing says bad time--and possibly hypothermia--like a wet sleeping bag in the Arctic. The SealLine Storm Sack performed perfectly throughout the trip, keeping all of my critical gear dry. Despite its light weight it's rugged enough to handle a lot of normal daily use. tl/dr: As a compromise between weight and durability, the Storm Sack seems to get the balance just right, and it's pretty inexpensive, too."