Ask ten paddlers what keeps their kit dry and you will get two answers, delivered with equal confidence. Half will hold up a roll-top dry bag: light, cheap, squashable, the thing that has kept sleeping bags dry on rivers for forty years. The other half will tap the lid of a hard case: rigid, gasketed, latched, the box that survived a swim with a phone and a camera inside. Both groups are right. Both are also wrong about something, because the two pieces of kit solve different problems and fail in different ways. 💧
The confusion is understandable. Both are sold as "waterproof". Both have a picture of a kayak on the packaging. Both will keep a t-shirt dry in the rain. The differences appear when the water is not rain but a river, when the bag is not carried but dropped, when the contents are not a t-shirt but a phone with everyone's photos on it – and when you need to open the thing with cold, wet hands to get the phone out before the light goes.
This article does three things. It explains, without marketing, how a dry bag and a hard case each keep water out and what each is rated to survive. It goes through nine common situations – a kayak capsize, a multi-day sea trip, a rafting weekend, a beach with children, a sailing passage, a flight with gear, and more – and says which of the two works in each and why. And it finishes with the honest answer most experienced people arrive at: you usually want both, in specific roles. We sell one of the two, so we will be clear about where the other one wins. ⚖️
🔬 Part 1: How each of them actually works
The dry bag: a roll and three folds
A classic dry bag is a tube of coated fabric – PVC, TPU-coated nylon or polyester, or lightweight silnylon for backpacking – with welded or taped seams and an open top. You fill it, press the air out, fold the top over itself three or four times, and clip the buckle. The folds trap the fabric against itself; water cannot follow the tight zigzag path into the bag, at least not quickly, at least not under low pressure.
That last part matters. A roll-top closure is splash-proof and briefly submersible, not pressure-proof. Hold a rolled dry bag under a metre of water for half an hour and most will let water in through the roll; some will let water in through the seams. Manufacturers know this, which is why most dry bags carry no IP rating at all, or a modest one, and why the instructions say "not designed for prolonged submersion". A dry bag's real strength is elsewhere: it weighs almost nothing, it packs flat, it takes any shape, it costs a fraction of a case, and it seals with one hand in three seconds. For clothing, sleeping bags, food and anything bulky and soft, nothing beats it.
Two variants extend the idea. Zip-seal dry bags use a waterproof zipper (a TIZIP or similar) instead of a roll-top; they are fully submersible if the zip is clean and lubricated, and much more expensive. And dry bags with a purge valve let you squeeze the air out for a smaller pack – at the cost of buoyancy.
The hard case: a gasket in a groove
A waterproof hard case – the Peli type – is a rigid shell of polypropylene or similar with an O-ring gasket set in a groove around the rim. When the latches close, they compress the gasket evenly all the way round; the seal does not depend on folds, tension or the user's technique. Cases like these are tested to IP67: dust-tight, and watertight to one metre of immersion for thirty minutes. Add a pressure-equalisation valve – a membrane that lets air through but not water – and the case can be opened after a flight or a temperature change without fighting a vacuum.
The rigid shell does something a dry bag cannot: it protects against impact and crush. A phone in a dry bag survives a swim; a phone in a dry bag that is then dropped on rocks or sat on in a raft does not. The shell also holds its shape, so a case with air inside floats predictably, and it can be padlocked, clipped and stacked.
Its weaknesses are the mirror image of the dry bag's strengths: it is heavier, it is bulkier and takes a fixed shape, it costs more, and it does not compress. Nobody carries a sleeping bag in a hard case. For more on what the IP rating means and does not mean, see our IP67 explainer.
The short version
| Question | Dry bag | Waterproof hard case |
|---|---|---|
| Rain, spray, splashes | Yes | Yes |
| Brief dunking (capsize, wave) | Usually, if rolled well | Yes |
| Submersion for minutes, under pressure | No (roll-top); zip-seal only | Yes (IP67: 1 m / 30 min) |
| Impact and crush | No | Yes |
| Floats with contents | If air is left inside | Yes, predictably |
| Weight and packability | Excellent | Poor |
| Seals reliably with cold, wet hands | Depends on technique | Yes – latches |
| Sand and grit | Tolerates it | Tolerates it; keep gasket clean |
| Lockable | No | Yes |
| Price per litre | Low | High |
With that in mind, here are the nine situations where the choice actually decides whether your kit survives. 👇
🛶 Part 2: Nine situations
1. The kayak capsize with your phone on deck 📱
The most common water accident in Europe is not a shipwreck. It is a recreational kayak or sit-on-top tipping in flat water, thirty metres from a beach, with a phone in a mesh pocket or a dry bag clipped to the deck. The kayak is fine, the paddler is fine, and the phone is either on the bottom or, if it was in a dry bag, floating away with a wet corner.
What actually happens to a dry bag in a capsize: it goes under, it is pulled through the water as the kayak rolls, and the roll-top is briefly under pressure from the wrong side. A well-rolled bag with plenty of air in it survives this nine times out of ten. The tenth time the user rolled it twice instead of four times, or clipped it with the top half-open, or the bag was old and the coating had cracked at the fold. The failure is not the material; it is the closure, which depends on the person.
Verdict: hard case. For the one item that must stay dry and must be found again – the phone, and with it the keys and the card – a micro case with a lanyard wins. It seals the same way every time, it floats, and it clips to the deck line. Peli's 1040 and 1050 are sized for phones; the 1020 and 1060 add space for a wallet and keys. Everything else in the kayak – the jacket, the lunch, the towel – is dry-bag territory, because it does not matter if it gets a little damp and it does matter that it weighs nothing.
2. The multi-day sea kayak or canoe trip ⛺
Five days on the coast, a tent, a sleeping bag, food, stove, spare clothes, and a hatch that is "watertight" in the brochure and damp in reality. This is the situation the dry bag was invented for. Soft, bulky, forgiving contents; hatches that reward things that squash into corners; a weight budget that punishes rigid boxes. Ten dry bags of different sizes, packed by category, is how expedition paddlers have done it for decades, and it still works.
Two things on the trip do not belong in a dry bag: the electronics and the fire-starting kit. A phone, a GPS or a satellite messenger, a camera, a power bank, a headlamp, batteries – these need to stay bone dry for five days, they are damaged by the condensation that builds in a hatch, and they are the first things you reach for in an emergency. The same goes for matches, a lighter and a first-aid kit, which must work the moment they are opened.
Verdict: both, in fixed roles. Dry bags for everything soft and bulky; one small hard case (a 1200 or 1300 class) for electronics and emergency kit, stowed where it can be reached from the cockpit. The case doubles as the "grab box" if the boat has to be abandoned. Our kayak packing list sets out the full kit.
3. The rafting or packrafting weekend 🌊
Whitewater changes the physics. The boat hits rocks; the gear inside hits the boat; the gear lashed on top hits the water at speed and drags. A dry bag on a raft is squashed, stepped on, used as a seat, and pulled under for seconds at a time in a hole. Most survive – rafting dry bags are heavy PVC for a reason – but what is inside them takes every impact, and the bags themselves are what the guides call "consumables".
Anything rigid, valuable or fragile – a camera, a drone, a phone, glasses, medication – is in danger in a soft bag on a raft not from water but from the raft. It is the impact that kills it. A hard case lashed into the boat takes the knock, floats if the boat flips, and keeps the contents dry while it is upside down in the river.
Verdict: hard case for anything with a screen or a lens; dry bags for clothes, and expect them to be damp by Sunday. On a packraft, where weight is everything, a single micro case for phone and keys plus a small dry bag is the usual compromise – and the case is clipped to the boat, not to you, because a boat is easier to find than a person's pocket after a swim.
4. SUP touring and the swim to the shore 🏄
A paddleboard has no hatch and no deck; everything is on top, in the sun and the spray, held by bungees. Falls are routine and the board is often not where the paddler is. The classic SUP loss is not the phone going into the water – it is the phone floating away from the board in a dry bag that was not clipped on, or sinking in a dry bag that had all the air squeezed out for a neat pack.
The two rules for a board: everything must float, and everything must be attached. A dry bag with air in it floats; a dry bag packed tight does not necessarily. A hard case with a phone and keys floats regardless and has a lanyard eye. On a long touring paddle with lunch, spare layer and water, a deck dry bag for the bulk and a micro case for the valuables, both leashed to the board, is the standard setup.
Verdict: micro case for the valuables, leashed; dry bag for the rest, also leashed. We went through the whole board kit in our SUP gear guide.
5. Sailing: salt, weeks and the wet locker ⛵
Nothing on a sailing boat is dry for long. Lockers sweat, bilges slosh, salt spray gets into every zip and every seam, and the boat moves for days without stopping. Gear that is not damaged by a single splash is damaged by weeks of salt humidity: cameras, laptops, handheld VHF radios, spare batteries, documents, cash, passports, a spare phone.
Dry bags do their usual job for clothing and bedding, and on a yacht their squashability is worth a lot. But a dry bag does not stop humidity: air inside a rolled bag is the same humid, salty air that was in the cabin, and it stays there for a week. A gasketed case with a desiccant sachet inside is a sealed, dry micro-climate. Its pressure valve lets it be opened in a hot cabin after a cold night, and its shell survives the locker.
Verdict: hard case for electronics, documents and anything the salt would kill; dry bags for clothes and bedding. On passage, many crews keep one case as the "ditch box" – documents, phone, EPIRB, torch, cash – clipped near the companionway so it goes into the liferaft in one hand.
6. The dive or snorkel boat day 🤿
Between dives, a boat deck is the wettest, sunniest, most crowded place a camera will ever be. Wetsuits drip on everything; tanks roll; somebody's fins land on your bag. Cameras, phones, spare batteries and cards spend the surface interval exposed to spray and heat, and the housing that keeps the camera safe underwater is opened right there to change batteries – which is where salt water gets onto the O-ring.
A dry bag on a dive boat keeps the towel dry and that is about all. For the camera, the phone, the batteries and cards, a hard case is the tool: it keeps them dry and shaded, it gives you a clean, dry surface to open the housing on, and it does not mind being stood on. A padded interior stops the batteries and the lens knocking each other every time the boat hits a wave.
Verdict: hard case. Our dive trip packing guide covers the full list.
7. The beach with children and sand in everything 🏖️
The beach is not a serious water environment and it destroys more phones than most rivers. Sand gets into the roll of a dry bag and into the teeth of any zip; sun cream coats everything; a wave arrives while everyone is looking the other way; and small hands open bags to find the snacks. A dry bag on a beach is a bag with sand in the seal and the phone somewhere in the bottom under a towel.
For the beach, what matters is a container that seals without care, keeps sand and cream out, floats if it goes in, and is small enough to be carried into the water by the adult who is going for a swim. That is a micro case: phone, car key, cards and cash in a 1040 or 1050, lanyard round the wrist or through the swim shorts, and the whole family's day is safe even when the towel is not.
Verdict: micro case for the valuables; a cheap dry bag or a tote for the towels. Rinse the case gasket in fresh water at the end of the day and it will do this for years.
8. Flying with gear that must arrive dry and intact ✈️
Not every water situation is on the water. Gear for a paddling or diving holiday has to get there first, in a hold where baggage is crushed, dropped, rained on and, occasionally, opened. A dry bag inside a suitcase is a good way to keep wet or sandy kit away from clean clothes on the way home; it is a poor way to protect anything rigid or valuable on the way out, because it protects against nothing but water.
A hard case in the hold does what the dry bag cannot: it keeps the camera, the dive computer, the drone, the electronics and the regulators from being crushed, it locks, and its pressure valve equalises the cabin-pressure change so the lid opens at the other end. On arrival, the same case becomes the boat box, the beach box and the dive-day box.
Verdict: hard case as checked baggage for the valuable, rigid gear; dry bags packed flat inside it for use at the destination. The two travel well together – the bags weigh nothing and fill the gaps in the case.
9. Canyoning, caving and wading with a phone 🧗
Canyoning and cave trips combine everything: full submersion, jumps, abrasion on rock, cold water and hands that are numb and wet for hours. A phone or a camera on such a trip is under water for minutes at a time, hits rock, and must be opened with gloves on. A roll-top dry bag is the wrong tool on every count: it is not rated for the submersion, it does not protect against the impact, and it cannot be reliably re-rolled with cold hands.
Canyoners have known this for years, which is why the small hard case is standard kit in canyoning packs, usually inside a heavy-duty canyoning dry bag that provides the buoyancy for the whole pack. The case holds the phone, the car key, a headlamp battery, a small first-aid kit; the bag holds the rope and the lunch.
Verdict: hard case for anything that must survive being under water and hitting rock; a burly dry bag around it for flotation and bulk. Choose a case that fits the pack's shape – the 1200 and 1300 are the usual choices – and clip it in.
📱 Micro cases for the phone, keys and cards – the one thing that must not sink
🧩 Part 3: The system most people end up with
Read the nine situations again and a pattern appears. The dry bag wins whenever the contents are soft, bulky, cheap or replaceable, and whenever weight and packability decide the trip. The hard case wins whenever the contents are rigid, valuable or fragile, whenever submersion is likely rather than possible, whenever impact is part of the environment, and whenever the container has to be sealed by someone who is cold, wet, tired or eight years old.
That is why experienced people carry both, in fixed roles rather than as alternatives:
- One micro case for the phone, keys, cards and cash – the "must not sink" set – on a lanyard, always in the same place. A 1040, 1050 or 1060 depending on the phone and what travels with it.
- One small or medium case for the electronics and the emergency kit on longer trips – camera, GPS or messenger, power bank, headlamp, first aid, fire – a 1200, 1300 or 1400, or a Storm iM2100 / iM2200, clipped into the boat.
- Dry bags for everything else, by category: sleeping kit, clothes, food, the wet-return bag for the way home.
The cases are the expensive part and they are bought once. The dry bags are cheap and they are replaced as the coatings crack. Together they cost less than the phone they are protecting.
Weight and space, honestly
A micro case for a phone weighs a few hundred grams and takes the space of a thick paperback. A 1200-class case weighs around a kilogram empty and needs a proper spot in the boat. A dry bag of the same volume weighs a fraction of that and disappears when empty. On a day trip, the difference is irrelevant. On a week-long expedition with a weight budget, it is real, and it is why the case list above is short: the cases carry only what actually needs a case.
Sealing technique – the part nobody teaches
Dry bags fail at the roll. Fold the top flat, press the air out (leave some for flotation if the bag must float), roll at least three full turns – four is better – keeping the roll tight and straight, then clip. Never roll over a lumpy load; the fold has to lie flat. Never overfill; a bag rolled twice because it was too full is a bag that leaks. And check old bags: coatings crack at the fold line, and a crack is a leak.
Hard cases fail at the gasket. Before closing, run a finger round the O-ring and the groove to clear sand, hair and grit; a single grain of sand across the gasket is a leak path. Close all latches, not just the ones you can reach. Rinse the case in fresh water after salt or sand and let the gasket dry before storage; a little silicone grease once a season keeps it supple. Do not open the case under water or with water pooled on the lid – tip it first. And remember that the valve equalises pressure, not water: it is a membrane, and it needs to be kept clean.
📦 Small and medium cases for electronics, cameras and the emergency kit
🧭 Choosing the size: what goes in the case
Phone only: the 1040 and 1050 take a large phone in a slim protective cover; check your phone's dimensions against the internal size, because phone cases add millimetres. Phone plus key fob, cards and cash: the 1020 or 1060, which also fits a small power bank. Compact camera, action camera with spares, or a GPS with batteries: the 1120 to 1200 class. Mirrorless camera with a lens, or the expedition electronics set: the 1300 to 1400 class, or a Storm iM2100 / iM2200, with foam or a padded divider set. The family's day-trip electronics or a dive-boat camera set: the 1450 and up.
Two practical notes. Choose a bright colour for anything that may end up in the water – yellow and orange are visible on a river in a way that black is not. And buy one size larger than the bare minimum: a case packed to the brim is hard to close cleanly, and the gasket needs a clear rim to seal.
✅ The checklist
Before you go:
- ☐ Phone, keys, cards, cash in the micro case, lanyard attached, case tested by closing it and dunking it in a sink.
- ☐ Electronics and emergency kit in the small case, dry, with a silica-gel sachet.
- ☐ Gaskets checked and clean; all latches close.
- ☐ Dry bags checked for cracks at the fold; contents packed by category; some air left in the ones that must float.
- ☐ Everything that floats also attached – to the boat, the board or you.
On the water:
- ☐ Case opened only with both hands free and the lid tipped away from the water.
- ☐ Dry bags re-rolled fully after every opening – three turns minimum.
- ☐ Nothing loose on deck.
At home:
- ☐ Cases rinsed in fresh water, opened, gaskets dried; a little silicone grease once a season.
- ☐ Dry bags rinsed, dried inside out, stored unrolled.
- ☐ The wet-return bag emptied before it becomes a science project.
❓ Common questions
Are hard cases really submersible?
Peli Protector, Storm and Micro cases are tested to IP67 – one metre of water for thirty minutes – when properly closed with a clean gasket. That covers a capsize, a wave, a fall in a canyon and a swim to the shore. It does not cover diving with the case; for that you need a pressure-rated housing.
Does a hard case float with a phone inside?
Yes – micro and small cases contain enough air to float a phone, keys and cards with room to spare. A large case loaded with heavy gear may not; when in doubt, leash it.
Can I put a dry bag inside a hard case?
Yes, and it is a good combination for travel: the dry bags carry the soft kit and fill the gaps, the case protects everything from the hold. On the water, the reverse also works – a small case inside a big dry bag gives impact protection to the electronics and flotation to the whole pack.
What about the phone's own waterproof rating – do I still need a case?
A phone's IP rating is tested in still fresh water when new; it says nothing about salt, pressure, a cracked screen, an ageing seal or the phone sinking. The case's job is as much to keep the phone findable and floating as to keep it dry.
Is a zip-seal dry bag as good as a case?
For water alone, a good zip-seal bag is fully submersible and very good. It still offers no impact protection, the zip has to be kept clean and lubricated, and it costs as much as a small case. It is the right choice for soft kit that must stay dry in full submersion – a sleeping bag on a packraft – rather than for electronics.
🏁 The bottom line
A dry bag keeps water out of soft things cheaply, lightly and well, as long as someone rolls it properly. A waterproof hard case keeps water and impact away from hard, valuable things, every time, regardless of who closes it – and it floats. In a kayak capsize, on a raft, on a sailing passage, on a dive boat, on a beach with children, in a canyon and in an aircraft hold, the phone and the electronics belong in the case. On a multi-day trip and a paddleboard, the clothes and the sleeping bag belong in the bags. Buy the case once for the things that must not sink, buy the bags for everything else, attach all of it to the boat, and stop losing phones. 💧
Micro cases, small cases and everything in between are in our Water Adventures range – and if you are not sure which size takes your phone in its cover, or your camera and its spares, send us the dimensions and we will match a case before you order.
