Yes, a sealed dry bag with air trapped inside will generally float, at least for a while, because a properly rolled top holds a small air pocket. That said, a dry bag is not a flotation device and should never be treated as one. A PFD is the only thing that should be doing that job.
This one comes up because it seems like it should have a simple yes or no answer, and mostly it does, with one honest caveat worth being clear about up front.
Why do dry bags float?
When you roll a dry bag correctly, you're supposed to press out most of the air, but not all of it. That leftover pocket of air is what gives the bag some buoyancy if it ends up in the water. It's a small, useful side effect of good technique, not a feature engineered separately from the seal. The full method, including why a little air stays in on purpose, is in how to seal a dry bag.
Can you count on a dry bag to float if it goes overboard?
Not fully, and this is the part worth being honest about. Floating is a byproduct of a good roll, not a guarantee. A bag rolled with little to no air left inside, or one that's genuinely taking on water through a real failure, can sink. Water temperature and current matter more to your safety than whether a dropped bag floats. A dry bag should never be relied on as a safety device. That job belongs to your PFD, full stop, the same way it does on a downwind or outrigger run, covered in what an outrigger paddler clips in for a downwind run.
What actually keeps a bag from going overboard
The better question is how to keep it from ending up in the water in the first place. Clip it in. Every Wild Currents size has a clip point or a strap built for attaching to a deck line, rigging, or a thwart, and using it is a better plan than hoping the bag floats well enough to retrieve. If a bag does go over, treat it like any floating object: retrieve it if it's safe and easy to reach, and don't chase gear into conditions that ask more of you than the bag is worth.
Clip it, don't chase it
Wild Currents makes roll-top dry bags in 2 liter, 10 liter, and 20 liter, each with a clip point or detachable strap built in. Browse the collection.
Frequently Asked Questions
Do dry bags float when they fall in the water?
Generally, yes, if there's some air sealed inside from a properly rolled top. It's not guaranteed, especially if the bag is packed with little to no air left, or if it's actually failed and taking on water.
Is a dry bag a flotation device?
No. Never rely on a dry bag for personal safety. A PFD is the flotation device. A dry bag floating is a helpful side effect of a good roll, not a safety feature.
Why does my dry bag sink instead of float?
Usually because it's overstuffed or compressed with little air left inside, or because it's genuinely taking on water through a real failure rather than a rolling issue.
Should I clip my dry bag to my boat?
Yes. All Wild Currents sizes have a clip point or a detachable strap for exactly this reason. Securing it is a better plan than hoping it floats well enough to grab back.
Does the size of the dry bag affect whether it floats?
It can. A smaller bag often has proportionally more trapped air relative to its contents, while a fully stuffed 20 liter has less spare air and less buoyancy margin. Either way, clipping it in matters more than its size.