How to Choose a Waterproof Dry Bag and 5 Recommendations | One Bag to Keep Your Gear Dry for SUP, Kayaking, Fishing, and Festivals

Have you ever opened your backpack after a day of SUP on the river, only to find your change of clothes and towel completely soaked? I’ve done it once. It’s truly miserable. My clothes, which should have been dry, had absorbed all the river water and become heavy, and I regretted it the whole way home.

Summer leisure activities are always right next to water. The ocean, rivers, pools, rainy festivals. The more fun the place, the more it seems to come with the risk of your gear getting wet. That’s where a waterproof dry bag comes in handy.

In this article, I’ll introduce how to choose a dry bag for situations where you absolutely don’t want your gear to get wet—from SUP and kayaking to fishing and outdoor festivals—along with some recommendations that I’ve actually used and loved. I’ve also summarized key points you should know before buying so you don’t end up thinking, 'This isn't what I expected.'

What is a dry bag, anyway?

As the name suggests, a dry bag is a waterproof bag designed to keep its contents dry. Most feature a 'roll-top' structure where you roll the opening several times to seal it, which prevents water from getting in.

The materials are mainly tarpaulin or PVC-coated fabric; you might think of tent fabric as a close comparison. It’s smooth and repels water, so it’s completely unfazed by rain or splashes.

However, there is one important thing to note here. Even though we call them all dry bags, their performance varies significantly between 'splash-proof' and 'fully waterproof.' If you buy one without knowing this difference, you might end up in a situation where you think, 'It said it was waterproof, but it got wet inside when I submerged it.' I’ll explain this in detail next.

Common mistakes when choosing a dry bag

Confusing splash-proof with fully waterproof

This is honestly the most important point: there are two types of waterproof bags—those that can withstand rain and splashes, and those that won't get wet inside even if submerged in water.

The basic rule for a roll-top is to roll it tightly at least three times, preferably four or five. If you don't roll it enough, water will get in through the opening no matter how waterproof the fabric is. In fact, I once made the mistake of only rolling it twice, and when a wave hit me on the breakwater, the towel inside got damp. If it's just rain or light splashes, rolling it properly is enough. But in a submersion scenario, like falling off a SUP with the bag, water can seep through the seams. If you need complete protection against submersion, you must choose one with a 'seamless' structure where the seams are welded using high-frequency technology.

Choosing a single-strap model

As the capacity increases to 20L or 30L, the gear inside gets heavier. Carrying that on a single shoulder is honestly tough over long distances. Your shoulder will scream. If you're carrying a significant amount of gear, a backpack style that you can carry on both shoulders is definitely more comfortable.

Falling for cheap, transparent PVC

Clear types that let you see the contents are convenient, but cheap PVC can harden in low temperatures and crack one day. They are especially prone to deterioration if stored in a car during winter. If you choose a transparent type, it's better not to compromise on material quality.

The ideal conditions for a dry bag in situations where you don't want to get wet

Choose the waterproof level that fits your purpose

Start here. The required waterproof level is determined by 'what you are doing.' For rainy festivals or fishing on a breakwater, splash-proof is sufficient. For activities where there is a possibility of submersion, like SUP or kayaking, choose a fully waterproof bag with welded seams. Both over-spec and under-spec are a waste of money.

Decide the capacity based on your needs

A good rule of thumb is 5–10L for valuables only, 20–30L for day trips, and around 40L for overnight activities. If you only need to carry a wallet, smartphone, and a light jacket, buying a 40L bag will leave you with too much empty space.

Check if it is designed to "float"

It is surprisingly easy to overlook, but if you are using it for water activities, the ability to "float" is a major source of peace of mind. If it is a type that floats on the water surface when you roll the top and trap air inside, the bag won't sink even if you accidentally let go of it.

This is the point I want to emphasize most strongly when choosing a dry bag. Waterproofing is often thought of as the "ability to keep contents from getting wet," but the real terror on the water is not "getting wet," but "sinking and never coming back." A bag containing your wallet, keys, and smartphone disappearing into the depths of a river or the bottom of the sea... doesn't that make you shudder just thinking about it? A floating bag not only protects your belongings but also prevents the worst-case scenario of losing the bag entirely. For kayaking and SUP, this one point can make all the difference.

By the way, there is a rating called "IPX" as a guide for waterproof performance. IPX4 is the level that "withstands water splashes from all directions," and IPX8 is the highest level that "does not allow water ingress even when continuously submerged." If you roughly remember that the higher the number, the stronger it is, you won't get confused when choosing.

5 Recommended Dry Bags

1. Montbell Dry Bag Tube 15L (The peace of mind of a domestic brand, start with this one)

The first one I want to mention is, of course, Montbell. It is a domestic brand that everyone who loves the outdoors knows. It is a tube type with a round bottom, and it seals securely when fastened with the buckles on both sides.

What makes it good is the reliability of the material and stitching. The tarpaulin-based fabric is flexible yet tough. It is also lightweight and can be rolled up compactly. Since it is a clear type, you can see what is inside, which is a subtly helpful point that prevents you from wondering, "Wait, where did I put my towel?"

This is a classic item I want people to pick up first if they are buying their first dry bag and don't want to make a mistake.

2. MARCHWAY Dry Bag Roll Top (A versatile player with a choice of capacities)

This MARCHWAY is perfect for those who want to "try it out easily first." Its strength lies in the wide range of capacities available—5L, 10L, 20L, 30L, and 40L—allowing you to choose the perfect size for your needs.

Made of 500D tarpaulin fabric, it handles rain and splashes easily if you roll the top properly. It comes with a detachable, adjustable shoulder strap, so you can carry it over your shoulder or cross-body. It protects your belongings from water, snow, mud, and sand, so I think it is a good idea to keep one at home not only for leisure but also as a disaster prevention supply.

It is incredibly versatile. If you were told to "choose just one," this is the one that is unlikely to disappoint most people.

3. Haimont Floating Dry Sack 30L (A serious choice for those who don't mind submersion)

For those who take water activities a bit more seriously, I recommend this Haimont. It is a 30L large-capacity backpack style that you can carry on both shoulders. And as the name suggests, it is "floating"... meaning it floats on water when rolled and fastened.

What is even better is that it comes with an IPX8-rated waterproof smartphone case. It solves the problem of wanting to take photos while kayaking or SUPing but being afraid of dropping your phone in the water. This type shows its true value in activities where you get thoroughly splashed, like rafting or fishing.

For those who engage in "activities where getting wet is a given," this will be a very reliable partner.

4. OverBoard Dry Flat Bag 15L (A high-performer from a British marine brand)

From here on, let's look at something a bit different. OverBoard is a brand specializing in waterproof gear from the UK. Since it is used not only for marine leisure but also at rescue sites and construction sites, its waterproof quality is guaranteed.

This dry flat bag is made of lightweight nylon with a tear-resistant TPU coating. It can be folded flat when not in use and floats properly on water. It seals the opening securely with a unique "Fold Seal System." As the name suggests, it has a flat shape, making it easy to fit against your body and comfortable to carry.

I think this is a great choice for those who want something a bit different from the standard, or for those who are particular about their gear.

5. Breakwater Supply Meanhigh Dry Bag 25L (A clever one that separates wet and dry items)

Finally, there is the 25L bag from Breakwater Supply, which hits the spot perfectly. What makes this interesting is that it has a mesh pocket on the front called a "wet pocket."

You can store wet swimsuits, gloves, or socks separately from your dry clothes. Plus, because it's breathable, they can dry out a little while you're on the move. If you've ever struggled with where to put wet items after a trip to the beach or pool, you'll appreciate this design.

It also features 360-degree reflective printing and a reflective chest strap with a whistle, making you easier to spot when traveling in the dark. With welded seams, the waterproofing is solid, too. It's a reliable companion that's thoughtful down to the smallest detail.

Things to do for extra peace of mind besides using a bag

Even after you get a dry bag, how you use it makes a difference. First, put your valuables in a zip-top bag before tossing them inside. This creates a double layer of defense and significantly increases your peace of mind.

For your smartphone, it's convenient to have an IPX8-rated waterproof pouch, especially if you choose a bag that doesn't come with one. It will allow you to take photos without worry, even while on a kayak.

Also, make it a habit to separate wet and dry items. Using stuff sacks or small pouches as dividers inside the bag will keep your gear from getting messy. You can even use this method as a substitute if your model doesn't have a wet pocket.

Summary

A waterproof dry bag is a tool that completely eliminates the anxiety of "not wanting things to get wet." It makes summer leisure activities much lighter and more carefree.

When choosing one, first determine the level of waterproofing that suits your needs. For rain and splashes, simple waterproofing is fine; if there's a possibility of submersion, go for full waterproofing with welded seams. As long as you get that right, you won't make any major mistakes. After that, just consider the capacity and whether it's comfortable to carry. Those three points are enough.

I became inseparable from my dry bag after I once submerged my gear while playing in a river. Once you know the peace of mind that comes with knowing your belongings are dry, you can't go back to a regular bag.

To fully enjoy the summer that comes around every year, I hope you find one here that fits your style of play. Take your time and choose carefully.