There's a big difference between a backpack that's fine for a quick two-minute walk to a lido and one that'll hold up to over an hour on the coast path with wet kit on the way back. If you're swimming somewhere you can't just park up and walk ten steps to, that difference really matters.
It’s why we've put together this handy guide to help you find the best waterproof backpack for wild swimming, not just one that says "waterproof" on the label.
Why a proper waterproof backpack matters
Like it or not, a lot of wild swim spots aren't conveniently located right next to a car park. Coastal coves, tarns, and quieter river spots usually require a bit of a trek, sometimes on uneven ground, and often in the unpredictable Great British weather.
It's not just about keeping your things dry anymore, it's about carrying weight comfortably over fair distances, having your hands free, and not ending up with a soaked back from rain or your own kit dripping through from the inside.
This is really where waterproof backpacks should be your go to. If you're only walking a few minutes from the car, a dry bag or waterproof tote will usually do the job just fine. But once you're covering some distance, a backpack built for the job is best.
What makes a backpack "waterproof" (and what doesn't)
Same as with any waterproof wild swimming gear, the word usually gets used pretty loosely.
Water-resistant backpacks are made from a treated fabric that'll shrug off drizzle, but they're not built to survive sustained rain or a splash from a bag going down on wet ground. Most regular outdoor backpacks fall into this category.
Waterproof fabric with standard zips is a step up, the material itself won't soak through, but stitched seams and normal zip closures are still weak points. Water finds its way in eventually.
Fully waterproof construction means welded or taped seams and a roll-top or sealed closure, no stitching for water to get through, and a closure that actually seals rather than just covers. This is what you want if you're walking any real distance to a swim spot, especially somewhere exposed.
What to look for in a wild swimming backpack
Capacity
How much you need depends on the trip. A quick after-work dip needs a lot less kit than a full day out. As a rough guide:
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20 to 25L – a towel, dry clothes, and not much else.
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30 to 35L – enough for a robe, towel, a flask, and a bit of food.
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40 to 45L – a full day's kit, including robe, towel, spare layers, food, a flask and more .
Wet and dry separation
This is the detail that makes the biggest difference day to day. After a swim, you've got wet kit going back in the bag, and you don't want it soaking your dry clothes or your phone. A dedicated wet compartment, or a smaller zip-out dry bag inside the main pack, keeps the two separate without you having to think about it.
Comfort over distance
A backpack that's fine for ten minutes can feel very different after an hour. Padded, adjustable straps make a real difference, and a supportive back panel stops the bag digging in when it's loaded up. Chest straps and waist belts will also help support the weight. If you're regularly walking further to reach your swim spot, this is worth paying attention to, not just an afterthought.
Closure type
Roll-top closures give you the best seal and let you adjust the bag's size depending on how much you're carrying.
External pockets
Useful for things you want quick access to (phone, car keys, snacks) without digging through the main compartment. Just be aware that external pockets are often water-resistant rather than fully waterproof.
Durability
These bags have a tough life. They get put down on wet rocks, dragged in and out of car boots, and loaded with damp kit trip after trip. Reinforced base panels, quality zips, and solid stitching around the straps all add up to a waterproof bag that lasts for many years..
Wild Moose waterproof backpacks
Our roll-top waterproof backpack is built for wild swimmers, hikers, and anyone who needs to carry a proper day's kit without worrying about the weather.
The main compartment is fully waterproof, made from a tough waterproof tarpaulin that shrugs off rain, splashes, and mud, with the roll-top closure keeping everything sealed even if the bag ends up on wet ground. It's got padded, comfortable straps for the walk in and out, and enough room for a robe, spare layers, and a flask, with space to spare if you're carrying for two. It features a separate zip-out dry bag so that you can keep your wet and dry kit apart. It also has 2 handy side pockets for flasks, a flat pocket that fits an OS map and several loops to attach other items such as walking poles.
Frequently asked questions
What is the best waterproof backpack for wild swimming?
It depends on how far you're walking and how much you need to carry. For a longer walk in or a full day's kit, a 40–45L roll-top backpack like ours gives you a fully waterproof main compartment and enough room to carry for yourself, or a swim buddy too.
Is a waterproof backpack better than a dry bag for wild swimming?
It depends on the trip. A dry bag is lighter and packs down small, ideal for short walks with minimal kit. A backpack is the better choice once you're carrying more, walking further, or want your hands free, especially over uneven ground.
Do waterproof backpacks keep everything completely dry?
A backpack with a sealed roll-top closure and welded seams will keep the main compartment dry through rain,splashes and even a brief full submersion. External pockets are usually water-resistant though, rather than fully waterproof, so it's worth keeping anything that absolutely can't get wet, like a phone, in the main compartment or a small dry bag.
Can I carry a waterproof backpack while swimming?
No, waterproof backpacks are designed to protect your kit on the way to and from the water. Whilst the backpack would keep your gear dry in the water, the straps could be a danger/hindrance if they snagged on an underwater object. If you need to keep valuables with you in the water, a small dry bag inside a tow float is the better option.