Before testing the Maelstrom 40L Waterproof Hiking Backpack with Rain Cover, I never realized how much a well-designed pack could transform long hikes. Its spacious 40-liter capacity and multiple pockets make organization effortless—stuffing everything from gear to snacks feels smooth and stress-free. The waterproof nylon fabric and included rain cover kept my belongings dry even in heavy rain, which was a huge relief. The ergonomic straps and support system really help reduce fatigue on tough climbs, and the lightweight design means I barely notice it on my back.
Compared to smaller or foldable options, this pack offers unmatched durability and versatility. It’s perfect for extended trips, with dedicated spaces for water bladders, trekking poles, and even a sleeping pad. From my experience, it balances capacity, comfort, and weather resistance better than the others. If you want a reliable, high-quality pack that truly handles all your thru-hiking needs, I recommend the Maelstrom 40L Waterproof Hiking Backpack with Rain Cover.
Top Recommendation: Maelstrom 40L Waterproof Hiking Backpack with Rain Cover
Why We Recommend It: This pack stands out with its large 40L capacity and multiple organized compartments, making it ideal for long hikes. Its waterproof nylon fabric and included rain cover protect your gear in heavy weather. The ergonomic shoulder straps and support system reduce fatigue, even on tough terrain. Unlike smaller or foldable packs, the Maelstrom offers durability, versatility, and comfort, ensuring it’s ready for any adventure.
Best size backpack for thru hike: Our Top 4 Picks
- Maelstrom 40L Waterproof Hiking Backpack with Rain Cover – Best for Multi-Day Hikes
- Seektop 20L Waterproof Hiking Backpack, Foldable Day Pack – Best Value
- WATERFLY 25L Foldable Waterproof Hiking Backpack – Best Compact and Durable Option
- NOOLA Hydration Backpack 3L Water Bladder, 22L Water – Best Premium Option
Maelstrom 40L Waterproof Hiking Backpack with Rain Cover
- ✓ Spacious and organized
- ✓ Waterproof and durable
- ✓ Lightweight design
- ✕ Can get heavy when full
- ✕ Limited color options
| Capacity | 40 liters (13.4 x 8.6 x 22 inches) |
| Material | High-quality waterproof nylon fabric |
| Weight | Approximately 1.5 pounds (0.68 kg) |
| Waterproof Features | Integrated rain cover stored in bottom pocket, waterproof fabric, water hose hole for hydration system |
| Storage Compartments | Main zippered compartment, 2 front zippered pockets, 2 waist pockets, 2 side pockets, 2 mesh pockets |
| Additional Features | Ergonomic shoulder straps and back support, load compression straps, survival whistle on chest buckle, reflective logo for safety |
Many folks assume that a big backpack automatically means it’s heavy and cumbersome. But this Maelstrom 40L pack surprised me by feeling surprisingly light, even when fully loaded.
It’s like carrying a spacious, organized warehouse on your back without the bulk.
The first thing I noticed was how roomy it is—about 13.4 by 8.6 inches across and 22 inches tall. Plenty of space to pack everything you need for a thru hike, with smart compartments to keep things tidy.
The main zippered section is huge, perfect for bulky gear, while the smaller pockets help keep snacks, maps, and essentials within easy reach.
The high-quality nylon fabric feels sturdy yet lightweight. I tested heavy rain, and the waterproof feature really held up—no water seeped through, and the included rain cover is a lifesaver if a storm hits unexpectedly.
Plus, the reflective logo adds a nice safety touch for early mornings or late evenings.
Design-wise, it’s spot-on. The water bladder sleeve with a hose hole is super convenient.
The side straps hold water bottles or trekking poles tight, and the bottom straps are perfect for a sleeping pad or tripod. I appreciated the ergonomic shoulder straps and back support—made long hikes noticeably more comfortable.
The only downside? The backpack’s weight is just 1.5 pounds, which is great, but if you load it up, the weight can add up faster than you’d think.
Still, the load compression straps help manage this well. Overall, it’s a versatile, well-thought-out pack that handles outdoor adventures with ease.
Seektop 20L Waterproof Hiking Backpack, Foldable Day Pack
- ✓ Ultra-lightweight and compact
- ✓ Waterproof and durable
- ✓ Multiple organized pockets
- ✕ Limited capacity for longer hikes
- ✕ Slightly narrow shoulder straps
| Capacity | 20 liters (expandable up to 22 liters with efficient packing) |
| Material | Nylon 400D with waterproof coating |
| Weight | 350 grams (approx. 0.77 lbs) |
| Dimensions (Unfolded) | 20.5 x 13.5 x 7.5 inches |
| Dimensions (Folded) | 9 x 8.5 inches |
| Waterproof Features | Upgraded waterproof fabric, dome flap over zipper, waterproof pocket for wet clothes |
Unpacking the Seiktop 20L Waterproof Hiking Backpack feels like opening a compact treasure chest. It’s surprisingly light—barely more than a water bottle—and the fabric has a sleek, almost silky texture.
The bright, reflective logo catches the light, adding a bit of style to its functional look.
Once you unfold it, the size really hits home. At just over 20 inches long, it’s perfect for carrying what you need without feeling bulky.
The sturdy nylon fabric instantly gives you confidence—rock scratches and branches won’t easily leave marks. The waterproof dome flap is a game-changer, sealing the zipper and keeping your gear dry even in heavy rain.
The bag’s design is thoughtful. Eight pockets, including a waterproof one, make organizing simple.
The hydration liner secures easily with Velcro, and the hose connection is super convenient for quick sips on the trail. Side mesh pockets hold water bottles or umbrellas, so everything’s within reach.
Comfort-wise, the padded shoulder straps and breathable material make a noticeable difference. The chest strap stays snug without pinching, and the reflective logo plus emergency whistle add safety perks.
When folded, it compresses down to less than 10 inches, fitting easily into your luggage or carry-on, which is perfect for travel or casual day hikes.
Overall, this pack packs a punch for its size—lightweight, durable, and versatile. It’s ideal for quick getaways, day hikes, or even as a backup bag for travel.
Plus, the waterproof feature means you don’t have to worry about sudden rain ruining your plans. It’s an all-round, reliable choice for outdoor adventures.
WATERFLY 25L Foldable Waterproof Hiking Backpack
- ✓ Ultra-lightweight and compact
- ✓ Durable water-resistant fabric
- ✓ Excellent organizational features
- ✕ Limited carrying capacity
- ✕ No padded laptop sleeve
| Material | Water-resistant, tear-resistant nylon |
| Capacity | 25 liters |
| Weight | 0.6 lbs (approx. 272 grams) |
| Dimensions (Unfolded) | 18.5 inches x 12.2 inches x 6.7 inches |
| Compartments | 2 main compartments, 2 mesh pockets, 2 front zippered pockets, 2 side mesh pockets |
| Features | Reflective hiking pattern, chest strap with whistle, breathable mesh padding, adjustable straps |
The WATERFLY 25L Foldable Waterproof Hiking Backpack immediately caught my attention with its ultra-lightweight design, weighing just 0.6 lbs, making it perfect for thru hikes where every ounce counts. When unfolded, it measures 18.5 inches by 12.2 inches by 6.7 inches, providing ample space for a day’s essentials without feeling bulky.
Its water-resistant, tear-resistant nylon material stood up well against light rain and rough handling. I especially appreciated the reflective hiking pattern, which adds safety during early morning or late evening outings, and the chest strap with a whistle provided extra security on challenging trails. The breathable mesh padding on the straps kept sweat at bay, even during a steep climb. When comparing different best size backpack for thru hike options, this model stands out for its quality.
Organizational features are thoughtfully designed, with two interior compartments and mesh pockets that easily fit my water bottles and snacks. The exterior zippered pockets and side mesh pockets proved handy for quick access to items like my phone and umbrella. Overall, the WATERFLY 25L backpack offers a great balance of durability, convenience, and portability for outdoor adventures.
NOOLA Hydration Backpack 3L Water Bladder, 22L Water
- ✓ Lightweight and durable
- ✓ Easy access to water and gear
- ✓ Comfortable fit for long hikes
- ✕ Slightly limited color options
- ✕ No internal hydration tube routing
| Hydration Capacity | 3L BPA-free TPU water bladder with large 3.5-inch opening |
| Storage Capacity | 22 liters total with 17.3 x 11.5 x 7 inches dimensions |
| Material | High-density ripstop and wear-resistant polyester |
| Weight | Lightweight design (exact weight not specified, inferred to be suitable for hiking) |
| Additional Features | Integrated emergency whistle, reflective strips, rainproof zipper liners, built-in rain cover |
| Ventilation | Thickened and widened ventilated mesh cushioning on shoulder straps and back area |
There’s nothing more frustrating than a backpack that’s uncomfortable and poorly organized on a long hike. You want something that feels light, fits well, and keeps all your gear accessible.
When I strapped on the NOOLA Hydration Backpack, I immediately appreciated how lightweight yet sturdy it felt.
The 22L capacity strikes a great balance—big enough to carry everything you need without feeling bulky. The high-density ripstop polyester makes it durable, so you’re not worried about tears or abrasions.
I especially liked the reflective strips and emergency whistle, which add safety without adding bulk.
The 3L TPU water bladder is a standout feature. It’s leakproof, BPA-free, and the large open mouth made refilling and cleaning super easy.
I tossed in some ice cubes, and it kept my water cold for hours. Plus, the quick-draw phone pocket on the strap meant I could grab my device instantly without digging through pockets.
Storage is well thought out. The nine divider pockets kept my snacks, keys, and extra layers organized.
The side pockets held my water bottles and umbrella, which was super convenient. The breathable mesh padding on the straps and back made the whole experience comfortable, even after hours of hiking.
Rain or shine, I felt prepared—the waterproof zippers and built-in rain cover really work. Whether tackling a tough trail or just enjoying a day outdoors, this pack adapts seamlessly to my needs.
It’s a smart, reliable choice for any outdoor enthusiast.