Dry bags are unique bags that are designed to keep your belongings dry when you are camping, participating in water-based activities such as boating or swimming, or in other outdoor situations where you may be exposed to water. There are a couple of different ways that these bags keep water out.
One primary design component that makes them waterproof is the material that they are made from. Most modern bags are made from PVC tarpaulin. This durable material is exceptionally waterproof, making it a great choice for creating bags that will keep your belongings dry.
Choosing the right material for the bags is only half the battle, however. You still have to deal with the seams of the bag. Most waterproof bags feature welded seam construction. In essence, the seams of the bag are melted together using heat, creating a watertight seal. As you can well imagine, this is a far better option than simply stitching the seams together since it eliminates all of the holes that water might be able to use to find its way inside the bag.
Finally, the closure of the bag also needs to be taken into consideration. You need to have an opening so that you can get your belongings inside. However, this opening needs to be able to seal tightly shut after the bag is full so that water cannot get inside. This is usually accomplished by having a roll top on the bag. In essence, you roll the top of the bag down several times. This creates a tight seal that is strong enough to keep water out.
Hopefully, this basic introduction gives you a better idea of how dry bags keep water out. Using one of these bags for your outdoor adventures is a great way to ensure that all of your belongings stay safe and dry.