A key part of any adventurer’s toolkit, a dry bag can help you organize your gear—think of it like a packing cube, only more rugged. After putting a total of 25 dry bags and sacks (a dry sack being the dry bag’s not-waterproof cousin) through the wringer, we think the Sea to Summit Big River Dry Bag is the most functional, durable, and versatile dry bag for the money. It’s easy to slide in and out of a pack and strong enough to drag over concrete, and it created the best waterproof roll-top seal of anything we tested.
The Sea to Summit Big River Dry Bag is for the outdoors enthusiast who needs one bag to do it all. We dragged this bag behind a boat through rocks, branches, and other roughage, and it was more durable and waterproof than many that were supposed to withstand more abuse. Meanwhile, its 420-denier nylon (which is not as burly as some other materials) makes this bag a decent option for compartmentalizing gear within a backpack without adding too much weight to your load.
The Big River Dry Bag has four loops (two on each side) in addition to two D-rings by the closure buckle that let you easily lash the bag to a boat, pack, bike, or car. It weighs 2.5 to 10 ounces, depending on the size you choose. As with many roll-top dry bags, the buckled seal creates a loop that you can easily use as a handle. It comes in seven sizes ranging from 3 to 65 liters in capacity, and in five colors.
The fabric of Outdoor Research’s Durable Dry Sack is 210-denier nylon with a polyurethane coating, which means it’s half as substantial as the material of our top choice. This bag withstood all our stress tests, however, so we think it’s plenty durable for long-term use in the field. The 55 L size weighs 7.5 ounces but is not necessarily meant for ultra-lightweight hiking, as it has the added weight of a vertical daisy-chain strip to lash the bag to a boat or vehicle. It could also easily attach to any MOLLE-compatible packs. A D-ring sits by the buckle, but it feels flimsier than the two adorning our top pick, and the Durable Dry Sack comes in only one largish size: 55 L.
This bag has no compression straps. But as with any roll-top dry bag or sack, we don’t think straps are necessary: You can compress a dry bag just by pushing out the air before you seal it. And if you’ll be using it on the water, it helps to leave some air inside so that the bag can float.
The Outdoor Research Ultralight Dry Sack is our number one choice for anyone carrying their load on their back. It’s great if you need to swim with a backpack on, or if you just get caught in the rain a lot. The ultralight fabric of this model is 40-denier ripstop with a polyurethane coating (don’t go dragging this sack around on the ground), and the 20 L size weighs 2.8 ounces. (There are four sizes, ranging from 5 L to 20L, although the smallest is currently sold out on Outdoor Research’s site.) It will maintain its dry interior as long as it has no holes, which seems obvious, but that means no sharp objects like keys or forks in or around the sack. (If you really need waterproofing for that stuff, a hard case is better.) These sacks are best for holding clothing and other soft goods, and they’re often useful for compartmentalizing the inside of a large backpack.