Do You Need a Waterproof Backpack for Travel?

By Fred Perrotta
Woman wearing a yellow rain coat and water-resistant travel backpack

You’re planning your next trip somewhere rainy like London or Southeast Asia. You’ll have your laptop with you so you don’t want to risk getting anything wet.

Do you need a waterproof backpack for the trip? Or is a water-resistant travel backpack enough?

Let’s start by defining both terms.

Waterproof Backpacks

What Makes a Backpack Waterproof?

If a backpack is labeled waterproof, you can completely submerge the bag in water without letting moisture inside. Waterproof is more about being underwater than about being in the rain.

Waterproofness is for extreme conditions, like falling off a boat, not for a short walk through a light drizzle.

A waterproof backpack is only needed in situations where you might use a dry bag. They’re effectively the same product. A dry bag is useful for protecting your phone or keys when you’re tubing down a river or at risk of dropping them in the ocean.

Building a Waterproof Backpack

Making a waterproof bag, one that keeps your stuff dry even when submerged in water, is a huge endeavor.

Designers have to make sacrifices to build a waterproof bag. Every material needs to pass a submersion test, and the components must be assembled in a way that doesn’t create holes. The standard process of sewing fabric creates holes for water to seep through with every stitch. Those holes are too small to impact your travel backpack’s performance in the rain. But they matter if you submerge your bag in a lake.

Most companies approach waterproof assembly by welding thermoplastics, i.e. melting two pieces of fabric together using ultrasonic sound waves.

Welding is an expensive way to make a backpack and requires specific fabrics. Not every fabric can be welded. Surprisingly, many waterproof fabrics can’t be welded and therefore can’t be made into a truly waterproof bag.

Waterproof bags also must be simpler in design than sewn bags due to the limitations of welding. Most waterproof backpacks are designed with a bucket-like main compartment and one or two flat pockets. By necessity, a waterproof bag is simpler with fewer pockets and features.

You shouldn’t make those tradeoffs when buying a travel backpack. You’d be sacrificing the features that make a backpack a travel backpack—organization and accessibility—for a level of water protection you just don’t need for most trips.

Water-Resistant Backpacks

Backpacks made with waterproof materials are not necessarily waterproof backpacks.

Fabrics can be waterproof. Zippers can be waterproof. And yet, a backpack made with waterproof fabrics and waterproof zippers may only be water-resistant, not fully waterproof.

Few travel situations require a truly waterproof backpack. Water resistance, like what you’ll find in the Outbreaker Backpack, will be more than enough protection for trips to rainy cities

What does water-resistant really mean?

Unlike “waterproof,” which has a clear standard in bags, water-resistant is less well defined.

A water-resistant backpack might only keep your stuff dry in a drizzle or might perform well in a downpour. To understand where a backpack falls in that spectrum, check for two main factors: zippers and fabric.

If you see coated zippers on a backpack, that’s a clue your bag will perform well in light rain. Coated zippers keep water out of the bag in one of the most vulnerable places, since zippers are full of gaps holes. For an example, we use PU-coated racquet coil zippers on our backpacks.

Fabric is more complicated. Some “water-resistant” fabrics are simply tightly-woven nylons with a durable water resistant (DWR) coating applied to the back. No matter how tightly you weave a fabric, there will always be holes. Holes mean water can get through the fabric. Cheaper fabrics combat this issue with a coating to repel moisture. That coating works for a while but will degrade over time.

Higher-quality waterproof fabrics, like the X-Pac VX21 sailcloth that we use, have multiple layers to trap moisture and keep coatings from wearing off. Tortuga travel backpacks have both a layer of waterproof PET film and a weather-resistant coating to keep your stuff dry, even if you’re stuck in a downpour.

As its name implies, sailcloth was originally used for the sails of racing boats and is made to stand up to extreme conditions. Sailcloth is a premium fabric choice for maximum performance and durability.

The Bottom Line

A high-quality, water-resistant backpack will keep your stuff safe and dry in a rainstorm. If you throw a water-resistant backpack into a lake, however, your laptop may not fare as well. If you’re kayaking, bring a truly waterproof dry bag.

The Outbreaker Backpack is a water-resistant, carry-on-sized backpack designed for city travel. Learn more about the advantages of waterproof fabrics and all the other travel-optimized features built into the Outbreaker Backpack.

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