Waterproof packs keep gear dry in storms, on boats and at the beach.
These are the driest 40L picks.
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Quick Picks
- Best waterproof duffel: Thule Chasm Duffel
- Best roll-top: Haimont 40+15L Roll-Top
- Best tarpaulin: MIER 40L Duffel Backpack
- Best hiking: Maelstrom 40L Waterproof Backpack
- Best camera: RAINSMORE Waterproof Camera Backpack
Comparison Table
| Product | Best for | Capacity | Standout feature | |
|---|---|---|---|---|
| Thule Chasm Duffel | Best waterproof duffel | 40L size | 840D waterproof laminate | View |
| Haimont 40+15L Roll-Top | Best roll-top | 40-55L | Roll-top expands to 55L | View |
| MIER 40L Duffel Backpack | Best tarpaulin | 40L | Tarpaulin, stowable straps | View |
| Maelstrom 40L Waterproof Backpack | Best hiking | 40L | 9 pockets, water-resistant fabric | View |
| RAINSMORE Waterproof Camera Backpack | Best camera | 15.6″ laptop | 6 dividers, rain cover | View |
Detailed Reviews
1Thule’s Chasm is a rugged, weather-resistant duffel made from 840D nylon with a waterproof laminate. It has a wide-mouth opening and converts from duffel to backpack in seconds.
Internal mesh pockets organize small items. The Chasm comes in several sizes; choose the 40L version for carry-on and long-weekend trips. It is the duffel we would trust on a rainy boat dock or a dusty truck bed.
Pros & Cons
What we like
- Very tough 840D laminate
- Wide-mouth opening
- Converts to backpack
Watch out for
- Backpack straps are basic
- Pick the size carefully
Key Specs
- Capacity: choose the 40L size
- Fabric: 840D nylon, waterproof laminate
- Carry: duffel or backpack
- Organization: internal mesh pockets
2Haimont’s roll-top pack starts at 40 liters and expands to 55 liters, so one bag covers fast summer overnights and bulkier shoulder-season trips. Vertical compression straps shrink it down when it is not full.
A dual-density foam hip belt, shaped shoulder straps, an adjustable sternum strap and a breathable back panel make it carry more like a backpacking pack than a big daypack. It is a newer listing, so long-term durability data is still thin.
Pros & Cons
What we like
- Expands from 40L to 55L
- Roll-top keeps rain out of the top
- Dual-density hip belt
Watch out for
- Newer listing, few reviews
- Roll-top is slower to open
Key Specs
- Capacity: 40L, expands to 55L
- Closure: roll-top
- Hip belt: dual-density foam
- Rain cover: included
3The MIER duffel backpack is a heavy-duty, water-resistant tarpaulin duffel with padded backpack straps that tuck into a side pocket when you do not need them. It comes in 40L, 60L and 90L sizes.
Two haul handles and four grab handles make it easy to throw into a truck bed or boat, and the reinforced double bottom handles wet ground. It is our pick for gear-hauling trips where a zippered backpack would get soaked or scuffed.
Pros & Cons
What we like
- Tough, wipe-clean tarpaulin
- Straps stow away
- Many grab handles
Watch out for
- Simple interior
- Tarpaulin is stiff when cold
Key Specs
- Capacity: 40 liters (also 60L, 90L)
- Fabric: water-resistant tarpaulin
- Carry: backpack, duffel, grab handles
- Base: reinforced double bottom
4This version of the Maelstrom swaps to a more water-resistant fabric and spreads storage across nine pockets: the main compartment, two front zip pockets, two hip-belt pockets, two side pockets and two mesh pockets.
The brand lists the pack at about 13.4 x 8.6 x 22 inches, a tall and narrow shape that stays close to your back on narrow trails and in crowded train aisles. Hip-belt pockets are the standout here; snacks, a phone and a map stay reachable without stopping. Like the standard Maelstrom it has no real frame, so treat it as a big daypack rather than an overnight hauler.
Pros & Cons
What we like
- Two hip-belt pockets for snacks and phone
- Water-resistant fabric
- Slim profile for trails and transit
Watch out for
- No frame for heavy loads
- Back panel runs warm in summer
Key Specs
- Capacity: 40 liters
- Size: about 13.4 x 8.6 x 22 in (brand listing)
- Pockets: 9 including 2 hip-belt pockets
- Fabric: water-resistant nylon
- Frame: none
5RAINSMORE’s waterproof camera backpack has thick padded dividers, six adjustable sections, a 15.6-inch laptop slot, a rain cover and tripod straps.
It is a solid outdoor-ready budget pack.
Pros & Cons
What we like
- Thick dividers
- Rain cover
- Laptop slot
Watch out for
- Newer brand
- Generic harness
Key Specs
- Laptop: 15.6 in
- Dividers: 6
- Extras: rain cover, tripod straps
How We Chose
We compared capacity, fit range, weight, carry system, materials, pockets and carry-on dimensions across dozens of backpacks, then read verified owner feedback to find comfort and durability problems that spec sheets miss. We did not receive free products, and we do not claim hands-on testing. TOR Scores combine published specs, verified owner feedback and overall value. Related: our shortlist of the best 40L camping backpack.
Waterproof vs Water-Resistant Backpacks
Waterproof backpacks use roll-top closures, welded seams and coated fabrics, so they keep gear dry in heavy rain and spray. Water-resistant packs shed light rain but can leak at zippers and seams. For boating, kayaking and heavy rain, choose a roll-top dry bag backpack or add a rain cover and liner. If you are comparing options, our guide to the best 40L camera backpack is worth a look.
Duffel Backpack vs Travel Backpack
A duffel backpack is a duffel bag first and a backpack second. It has a big, simple main compartment, tough fabric and straps that stow away. A travel backpack has a harness built for walking and more organization. For a closer look, see our guide to the best 40L backpack travel picks.
- Choose a duffel for road trips, boat trips, gym bags, gear hauling and any trip where you mostly carry the bag from car to room.
- Choose a travel backpack if you will walk more than 15 minutes with your bag, take trains and buses, or move between hostels.
- Fabric. Tarpaulin and laminated fabrics, like the MIER and Thule Chasm, shrug off rain, mud and boat spray.
- Straps. Padded, contoured straps (Osprey Daylite Duffel) are comfortable for longer carries; thin webbing straps are only for short walks.
What to Look for in a 40L Hiking Backpack
Forty liters is the sweet spot between a daypack and a full backpacking pack. It holds the Ten Essentials, layers for changing weather, lunch, three liters of water and still has room left for a light sleeping bag on an overnight. Here is what separates a good hiking pack from a big school bag. We cover this in more depth in our roundup of the best 40L backpack for travel.
- Frame or no frame. Frameless packs (Maelstrom, Nerlion) are light and cheap but feel heavy above about 20 pounds. Internal frames (Osprey, Naturehike, N NEVO) move weight onto your hips and stay comfortable to 30 pounds or more.
- Hip belt. A padded hip belt carries most of the load. A thin webbing strap only keeps the pack from swinging.
- Back ventilation. Mesh or channeled back panels reduce the sweaty patch on hot climbs.
- Rain protection. Most packs are water resistant, not waterproof. A rain cover or a liner bag keeps your sleeping bag and spare clothes dry.
- Hydration. A bladder sleeve and hose port let you drink without stopping, which helps you drink enough.
- Access. Side zips, front shove-it pockets and hip-belt pockets save you from unpacking the whole bag for one item.
For long day hikes, a frameless pack is fine. If you plan to carry a tent, stove and sleeping bag, choose a framed pack with a padded hip belt.
Related guides: best 40l dry bag backpack, best 40l travel backpack waterproof, best 40l backpack duffel. Browse every pick in our Backpacks category.
Sources and further reading: National Park Service: the Ten Essentials, Leave No Trace: the 7 Principles and National Park Service: camping basics. Product specs come from brand listings on Amazon; always check your airline’s current carry-on size rules before you fly.
Frequently Asked Questions
Are 40L backpacks waterproof?
Most are water resistant; use a rain cover or liner, or choose a roll-top waterproof pack.
How do I clean a backpack?
Empty it, brush out dirt, hand wash with mild soap and air dry; avoid machine washing unless allowed.
Is 40L big enough for an overnight trip?
Yes for summer overnights with compact gear; cold-weather trips usually need 50L or more.
Is a 40L backpack carry-on size?
Many are designed around common carry-on limits, but airlines differ; check dimensions and your airline’s rules.
How much should a 40L pack weigh?
Frameless packs can be about 1 to 2 lb; framed hiking and travel packs often weigh 2.5 to 4 lb.
Final Verdict
The Thule Chasm and Haimont roll-top are the best waterproof 40L packs.
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