Waterproof Bags vs Dry Bags — What’s the Difference?

When it comes to keeping your kit dry, people often use waterproof bags and dry bags as if they’re the same thing. But while they serve a similar purpose, there are important differences — and knowing which one you need can make or break your next adventure.

Let’s break it down.

What Is a Waterproof Bag?

A waterproof bag is designed to resist water entry using materials like PVC or TPU. It may include zip-seal, flap, or roll-top closures.

Waterproof bags come in various forms. Backpacks, duffels, and totes and offer protection from rain, splashes, and the odd spill.

When to Use a Waterproof Bag

• Commuting or cycling in wet weather
• Travel and weekends away
• The beach or poolside
• Carrying valuables (e.g. tech or documents)

20-Litre Waterproof Dry Bag Backpacks with Comfort Shoulder Straps

These lightweight, stylish, waterproof backpacks are perfect for everyday protection, beach trips, and casual water exposure.

What Is a Dry Bag?

A dry bag is specifically built to be airtight, watertight, and highly durable. It typically features a roll-top closure system, which, when appropriately sealed, traps air, allowing it to float and keep your contents completely dry.

These are essential for:

• Paddleboarding or kayaking
• Wild swimming or boating
• Camping in unpredictable weather
• Keeping spare clothes and gear dry on the go

Featured Product: Watermelon 20-Litre Dry Bag Backpack

A customer favourite this dry bag combines personality, comfort, and full waterproof protection. With welded seams, padded straps and 20L capacity, it’s ready for any adventure.

Key Differences at a Glance

Benefits of the 20L Dry Bag Backpack

Our bestselling Watermelon 20-Litre Dry Bag Backpack doesn't just look great, It’s built for real-world adventure.

Here’s why it stands out:

• 100% Waterproof: Built with heavy-duty 500D PVC tarpaulin and a secure roll-top closure.
• IPX66 Rated: Fully protected against dust, solid objects, and powerful water jets from any direction.
• Floats in Water: When closed correctly (rolled tightly at least 3 times), it will float — keeping your gear safe.
• Reinforced Seams: Welded for full waterproof protection and long-lasting durability.
• Internal Zip Mesh Pocket: For quick access to essentials like keys, phone, or wallet.
• Adjustable Backpack Straps: Detachable, padded and comfortable to carry.
• Versatile & Rugged: 6 D-rings and a carabiner included, plus strong clasps and front grab handle.
• Easy to Clean: Wipe clean or use warm soapy water. Lemon juice helps remove stains.
• Weather-Resistant Design: Keeps out snow, sand, rain, and dirt.
• Dimensions & Capacity:
• 20L capacity
• H 50cm x W 23cm (cylindrical, rolled)
• H 60cm x W 37cm (flat, unrolled)
• Weight: 720 grams
• Storage Tip: Keep it in a cool, dry place away from direct sunlight when not in use.

So, Which One Should You Choose?

• Choose a dry bag if you need airtight protection for water sports, unpredictable environments, or full exposure.
• Choose a waterproof bag for day-to-day use, light activity, or when your main risk is rain, not full immersion.

Many Salty Kit customers choose both. Using a dry bag inside a waterproof backpack or switching depending on the adventure.

FAQs: Waterproof Sacks vs Dry Bags

What is the difference between a waterproof bag and a dry bag?

A waterproof bag resists rain and splashes but may not be airtight or fully submersible. A dry bag is designed to be completely waterproof and often floats when properly sealed.

Can dry bags be fully submerged?

Check your IPX rating for this question.  

• IPX6: Pressure-tested against strong currents and surface chop
• IPX7: Handles short descents up to 1 meter, like reef diving
• IPX8: Certified for deep diving conditions and extended submersion

Our dry bags are IPX66 tested and will survive waves and a dunking when sealed correctly using the roll-top method.  Its a good idea to keep valuables in an IPX8 container inside for further protection.  Our bags are ideal for water sports, camping, and river crossings.

Are all waterproof backpacks also dry bags?

No. Many waterproof backpacks are water-resistant or splash-proof but not fully sealed like dry bags. Dry bags use a roll-top and welded seams for 100% protection.

Do dry bags float?

Most dry bags float when properly sealed because the roll-top traps air. However, overloading or not sealing correctly can affect buoyancy.

Can I use a dry bag as a daypack?

Absolutely. Many dry bags (like our 20L range) have shoulder straps for comfort, making them perfect for hiking, beach days, and everyday use in wet environments.

Waterproof bags and dry bags are both essential — but they serve different purposes. Whether you're battling waves or dodging puddles on your morning commute, Salty Kit has the kit to keep your gear safe, dry, and stylish.

“A good waterproof bag protects your gear. A great one protects your day.” — Salty Kit