To seal a roll-top dry bag: fill it no more than two-thirds full, press the air out, hold the collar edges flat together, fold the collar down three tight times in the same direction, then clip the buckle. Three folds is the minimum that keeps water out. The flat first fold matters most.
Almost every "my dry bag leaked" story is really a "my dry bag was closed wrong" story (we say this with love, having lived several of them). The bag is simple. The technique is simple. But there are two or three small details that decide whether your spare layer comes out dry or comes out as soup.
Here's the whole technique, plus the reasons behind each step, so it sticks.
How do you close a roll-top dry bag, step by step?
- 1. Underfill it. Two-thirds full, maximum. The closure needs at least three or four inches of empty collar to fold. A stuffed bag can't roll, and an unrolled bag isn't a dry bag, it's a tote with commitment issues.
- 2. Press out the air, mostly. Squeeze the bag gently before you roll so the collar lies flat. Leave a little air in, on purpose: that's your flotation if the bag goes swimming.
- 3. Make the first fold flat and even. Bring the two stiffened edges of the collar together so they line up, then fold once, crisp, like the top of a paper lunch sack. A wrinkled or diagonal first fold leaves a channel water can follow. This is the step that does the sealing.
- 4. Fold at least three times. Same direction, each fold tight on the last. Three is the minimum, four if the collar has room. Each fold lengthens the path water would need to travel.
- 5. Clip the buckle. The buckle isn't the seal. The folds are the seal. The buckle just keeps the folds from unrolling and gives you a handle to clip into your rigging.
Why do dry bags leak even when closed?
Four usual suspects, in order of likelihood:
- Too few folds. One or two folds will survive splash and lose to immersion. Roll three.
- Overfilled bag. No collar left to roll. The fix costs nothing: carry less, or carry a bigger bag.
- Something in the fold. A strap end, a sleeve, a corner of a towel caught in the roll holds the fold open just enough. Clear the collar before you roll.
- Actual damage. A puncture or a worn seam, which is rarer than people think and easy to find with the test below.
How do you test whether a dry bag is sealed?
Two ways. The quick check: close the bag, then press down on it. If it holds pressure like a balloon and you hear no hiss, the roll is good. The thorough check (do this at home, once a season): close the empty bag, hold it underwater in a tub or sink for a minute, open it, and look inside. Dry means dry. A few drops mean re-check your fold count and look at the seams.
If your bag fails the tub test repeatedly with a good roll, it's the bag, not you. Our care and maintenance guide covers finding and dealing with damage.
Does this work in real conditions?
It does, which is the whole point of a roll-top. Closed properly, a welded-seam roll-top handles rain, spray, wave wash over a deck, and the kind of brief full dunk that happens when a board flips or a boat hulis. Closed in a hurry with one lazy fold, it handles approximately none of that. The technique is the waterproofing.
Ours are roll-top with welded seams, in five prints named for real water. The lineup is in the collection, and if you want the stories behind the prints first, join The Current Club, our email list.
Frequently Asked Questions
How many times should you roll a dry bag?
Three full folds minimum, four if the collar has room. Fewer than three will survive splash but not immersion. More than four usually means the bag was underfilled enough to size down next time.
Should you leave air in a dry bag?
Yes, a little. Trapped air keeps the bag floating if it ends up in the water. Press out most of the air so the collar rolls flat, but don't vacuum-pack it.
Can a properly sealed dry bag be submerged?
Briefly, yes. A well-rolled roll-top handles a dunk, a capsize, or wave wash. No roll-top is meant for sustained submersion at depth, so for electronics, add a small pouch inside as a second layer.
Why does my dry bag have water inside after a trip?
Most often: too few folds, an overfilled bag, or fabric caught in the roll. Check those three before suspecting damage. If the tub test still fails with a clean three-fold roll, inspect the seams and fabric for wear.
Do dry bag buckles keep water out?
No. The buckle holds the rolled folds in place and gives you a clip point. The folds themselves are what seal the bag, which is why fold technique matters more than buckle tension.