We tested the 35-liter Boundary, a roll-top bag with removable backpack straps. It has a 100D 18.5oz vinyl-coated polyester body with a 100D 30oz vinyl-coated polyester bottom and welded seams. It features a removable backpack harness with padded straps and a webbing waist belt.
Work hard, play hard, and go farther with the SealLine Boundary.
The Boundary let us down when it comes to waterproofness. Though it has an impressive construction, the top section above the shoulder straps is simply too short to allow you to easily get a three roll minimum when closing. When we were finally able to huff and puff and get in those rolls to squeeze the sides of the buckle together, we, unfortunately, discovered this dry bag is not as protective as we'd hoped. Though it protects well against splashes and rain, the top is too stiff to form a good seal against being submerged or even sprayed from the wrong direction with a garden hose. Tons of bubbles escaped when we pushed this sack underwater, and our testing towel got rather damp. When we filled it with water and walked/ran/jumped around, water readily splashed out without much trying. Like some other bags we tested, we found that filling this backpack full helps to hold the rolled top closed, but still isn't a perfect seal.
The DrySeal top helps block water, but unfortunately there's not quite enough space on the top of this bag to get a really secure roll to protect your gear.
Ease of Use
The Boundary is a large cylinder with an opening at the top. This requires you to stack the contents inside. Fortunately, the flat bottom assists in the process as it allows the product to stand upright unsupported. Though it's taller than it is wide, it's not nearly as tall and narrow as many of the options we tested, which helps a little bit when you're rooting around trying to find something. However, 35 liters of space as just a single large cavern can make it a bit difficult to stay organized and find one that one small item you need, particularly if you don't have an organizational system in place.
A slightly oval shape helps this bag to stand up more easily and not roll away when you set it down.
The backpack straps make it comfortable to carry, especially with lighter loads. The webbing waist belt on this model is unpadded and, therefore, quite abrasive when hiking with weight on your hips. If you find yourself hopping into a boat with this piece and wanting to take off the backpack harness, be aware that it's a rather involved process of velcro loops and unthreading several straps from buckles to get it off. Even when it finally comes free, there are two straps, and two buckles still left dangling off the bag. You can attach them together to provide some lash points for your sack if you desire. Putting the harness back on again is a similarly involved process.
The Boundary offers two unique features. The first is the DrySeal roll-top closure system. The lip of the bag is reinforced with two independent strips of thick material that assist in creating a tight seal. Previous versions of this bag had taller tops, giving you more material to work with when rolling it closed. That extra space made other versions exceptionally watertight. Unfortunately, the current Boundary just barely has enough material to get three rolls in, and it's a squeeze to do that. The rolls run into the top of the backpack harness area, which pushes against it in a bad way, ruining the integrity of what otherwise would be a good seal. So while we like the DrySeal system, we think it's not at its best.
The main body of the harness is easy enough to remove, though all the extra straps are a pain in the butt.
The second main feature of the Boundary is the removable backpack harness made up of adjustable padded shoulder straps, a sternum strap, and a webbing waist belt. This is another place where previous versions of this bag were much easier to use. The main attachment point of the harness is easy to remove, but the addition of load lifter straps means you have to un-thread the webbing from the top of the bag, as well as from the bottom where the shoulder straps attach. This is rather tedious and time-consuming. Even after you've removed the harness and the webbing waistbelt (separate from the harness), you're left with two dangling straps and the buckles from the load lifter straps still on the dry bag. Not the cleanest or the quickest design we tested, nor is it our favorite.
You have to unthread four buckles just like this one to get the backpack harness off, and two more to remove the webbing waist belt.
The Boundary is made of some beefy materials that are very resistant to punctures and abrasions. The 1000D vinyl-coated polyester is thicker on the bottom than the body, further adding to its durability. Welded seams add another degree of impressive construction to this tank-like bag. However, paired with all this intense material, SealLine has added plastic buckles and clips that just don't match with the rest of the bag, and make us worried about how it might hold up under years of intense sunlight and water usage. We're also not the biggest fans of the relatively thin, easy to fray webbing. So while we love the bag itself, we think the details are a bit lacking here.
Leftover straps after the removal of the backpack harness can make a makeshift backpack for lashing down this durable, but not so watertight dry sack.
The Boundary is about in the middle of the price range of bags we tested and performed slightly below average. If it's exactly what you've been looking for, it might be worth it for you. We, however, think it's not the most impressive model we tested and believe there are better options out there for this kind of money.
The SealLine Boundary is a highly durable, easy to use backpack model. While it may not be ideal for submersions or attaching to your paddleboard for the day, it is very ready to stand up to rainstorms and being scraped along the walls of a slot canyon.
Carrying the Boundary around is pretty nice, though we wish it was more watertight.