You capsized 200 metres from the shore, your phone was in a zip-lock bag inside your deck bag, and somehow water still got in. The screen is flickering, your car keys are soaked, and the drive home involves calling the RAC from someone else’s phone. A proper dry bag would have prevented all of it. They cost less than the excess on your phone insurance, they last for years, and they are the single most important accessory for any paddler who takes valuables on the water.
In This Article
- Why You Need a Proper Dry Bag
- Types of Dry Bags and Waterproof Bags
- Best Dry Bags for Kayaking and SUP in the UK
- Size Guide: What Capacity Do You Need
- Roll-Top vs Zip Closure
- Material and Durability
- IPX Ratings Explained
- How to Pack a Dry Bag Properly
- Dry Bags for Different Paddling Activities
- Caring for Your Dry Bags
- Frequently Asked Questions
Why You Need a Proper Dry Bag
Water Gets Everywhere
Even if you never capsize, water finds its way into kayak cockpits, SUP deck bags, and canoe hulls. Splash from paddle strokes, rain, waves breaking over the bow, and condensation inside hatches all conspire to soak anything that is not properly sealed. A standard rucksack or carrier bag offers zero protection in this environment.
Phones, Keys, and Wallets
Your phone is a £500-1000 device that dies permanently when submerged. Your car keys contain electronics that corrode with salt water exposure. Your wallet has cards that warp. A 5-litre dry bag costing £15 protects all three items from a full immersion capsize. The maths is obvious.
Safety Equipment
If you carry a VHF radio, personal locator beacon, or emergency phone, those items must work when you need them — which is precisely when conditions are worst. Storing safety equipment in a proper dry bag is not optional. The RNLI recommends carrying a means of calling for help in a waterproof container on every paddle.
Types of Dry Bags and Waterproof Bags
Standard Roll-Top Dry Bags
The most common design. A cylindrical bag made from coated nylon or PVC with an open top that you roll down 3-4 times and clip shut with a buckle. Simple, effective, and available in every size from 1 litre to 60+ litres. The roll-top closure is inherently waterproof when done correctly — there are no zips or seams to fail.
Dry Bag Backpacks
A dry bag with shoulder straps and sometimes a waist belt. These work as both a waterproof container and a carrying system for the walk to and from the water. Capacities typically range from 20-40 litres. The trade-off is that backpack-style dry bags are slightly less watertight than dedicated roll-top bags because the strap attachment points create potential leak paths.
Waterproof Pouches and Phone Cases
Small, flat pouches designed specifically for phones, wallets, and documents. Usually clear PVC with a roll-and-clip or zip-lock closure. These are cheap (£5-15), fit in a buoyancy aid pocket, and let you use your phone’s touchscreen through the plastic.
Dry Barrels and Boxes
Rigid containers with screw-top or clamp lids. Used mainly in expedition canoe touring where you need to protect fragile items (cameras, food) from being crushed as well as getting wet. Heavier and bulkier than bags but offer crush protection that flexible bags cannot.
Deck Bags with Waterproof Lining
Bags designed to attach to the deck of a SUP or sit-on-top kayak. Most are water-resistant rather than fully waterproof — they handle splash but not submersion. Useful for quick-access items but not for valuables you cannot afford to get wet.
Best Dry Bags for Kayaking and SUP in the UK
Best Overall: OverBoard Pro-Vis Waterproof Dry Bag 20L
About £30 from OverBoard direct, Amazon UK, or Go Outdoors. OverBoard is a UK-based brand that has been making dry bags for paddlers since 2002. The Pro-Vis range adds high-visibility reflective panels — surprisingly useful for being spotted by other water users in low light or when swimming after a capsize.
The bag is constructed from welded PVC tarpaulin (no stitched seams to leak), with a roll-top closure that seals tight. The D-ring attachment points let you clip it inside a kayak cockpit or to SUP bungees. At 20 litres, it holds a full change of clothes, phone, keys, wallet, and a lightweight towel. Submersion-rated — OverBoard tests their bags to 6 metres for 30 minutes.
Best Budget: Osprey Ultralight Dry Sack 12L
About £16 from Osprey, Cotswold Outdoor, or Amazon UK. Do not confuse this with Osprey the backpack brand making dry bags — this is a simple, lightweight roll-top sack in siliconised nylon. It weighs just 30g, packs down to the size of a fist when empty, and keeps your gear dry in rain and splash conditions.
The limitation is that it is not submersion-rated. For kayakers who capsize rarely and mainly want splash protection, it is perfectly adequate. For white water, sea kayaking, or anyone who expects to be fully in the water, spend more on the OverBoard or Sea to Summit.
Best Premium: Sea to Summit Hydraulic Dry Bag 20L
About £45 from Sea to Summit, Cotswold Outdoor, or Ellis Brigham. The Hydraulic range uses 600D TPU-laminated fabric — tougher than most dry bags and abrasion-resistant enough for dragging across rocks without puncturing. The wide oval opening makes packing easier than round-topped bags, and the purge valve lets you squeeze out excess air to compress the bag for storage.
This is the choice for sea kayakers, white water paddlers, and anyone who subjects their gear to rough treatment. The fabric is heavier than the budget options (the 20L weighs 280g), but the durability justifies it for regular use in demanding conditions.
Best Phone Pouch: Aquapac TrailProof Phone Case
About £20 from Aquapac, Amazon UK, or most kayak shops. Aquapac pioneered waterproof phone cases for paddlers and their TrailProof range is IPX7 rated (submersible to 1 metre for 30 minutes). The clear TPU window allows full touchscreen operation and the camera lens area is optically clear enough for photos. A lanyard loop lets you clip it to your buoyancy aid.
Best Backpack: Red Original Waterproof Backpack 30L
About £70 from Red Original or Amazon UK. A roll-top dry bag backpack with padded shoulder straps, a sternum strap, and an internal pocket. Red Original made their name in SUP and their bags are designed for the walk-to-water paddler who needs to carry gear to the beach, paddle for hours, then carry everything home dry. The 30L capacity fits a change of clothes, towel, snacks, and phone with room to spare.
Size Guide: What Capacity Do You Need
1-5 Litres
Phone, keys, wallet, snack bar. The minimum for a short paddle where you want your essentials protected. Fits inside a buoyancy aid pocket or clips to deck bungees.
10-15 Litres
Everything above plus a lightweight fleece or windbreaker. Enough for a half-day paddle where you want a dry layer to change into at the takeout.
20-30 Litres
A full change of clothes (including shoes), towel, lunch, water bottle, and electronics. The sweet spot for most day paddlers doing 2-4 hour sessions on UK rivers, lakes, or coastline.
40-60 Litres
Overnight gear for multi-day paddle camping. Sleeping bag, spare clothes, food, cooking equipment. Usually carried inside kayak hatches rather than on deck.
Multiple Bags Strategy
Most experienced paddlers carry 2-3 dry bags rather than one large one. A small (5L) bag for valuables that stays clipped to your person or buoyancy aid, and a larger (20L) bag for clothes that stores inside the boat. This way, if the boat is lost or separated from you, your phone and keys are still accessible.
Roll-Top vs Zip Closure
Roll-Top Advantages
- No mechanical parts to fail — the rolled fabric seal is inherently waterproof
- Gets more watertight with use as the fabric softens and moulds together
- Easy to compress out air before sealing
- Cheaper to manufacture (lower retail price)
Zip Closure Advantages
- Faster access to contents — unzip rather than unrolling
- Can partially open without compromising seal on the rest
- Looks and operates more like a conventional bag
Which Is Better for Paddling?
Roll-top wins for water sports. Zip closures eventually fail — sand, salt, and UV degrade the rubber seal over time. A roll-top closure has no failure points except user error (not rolling enough times). For a dry bag that protects your gear season after season, roll-top is the more reliable choice.
Material and Durability
PVC Tarpaulin
Heavy, extremely waterproof, and durable. Used in heavy-duty bags like the OverBoard range. Resistant to punctures and abrasion. The downsides are weight and the fact that PVC is not environmentally friendly — it does not biodegrade and is difficult to recycle.
TPU-Laminated Nylon
A lighter alternative to PVC that offers comparable waterproofing with better sustainability. Sea to Summit and many premium brands use TPU (thermoplastic polyurethane) bonded to nylon fabric. Lighter than PVC, more flexible, and recyclable at end of life. Slightly less abrasion-resistant than PVC at equivalent thickness.
Siliconised Nylon
The lightest option. A thin nylon fabric treated with silicone for water resistance. Excellent for weight-conscious paddlers and as a splash-proof liner inside deck bags. Not submersion-rated in most cases — the fabric itself is water-resistant but the seams may allow water through under pressure.
Weld-Sealed vs Taped Seams
- Welded seams — the fabric edges are heat-welded together, creating a bond as strong and waterproof as the fabric itself. This is the gold standard for submersible dry bags.
- Taped seams — the fabric is stitched, then tape is applied over the stitch holes. Less reliable than welding because the tape can peel over time, especially with UV exposure and salt water.
Always choose welded seams for any dry bag that must survive immersion.
IPX Ratings Explained
The IPX system rates water protection on a scale from 0 (no protection) to 8 (continuous submersion):
- IPX4 — splash proof. Handles rain and paddle splash but not submersion.
- IPX6 — powerful water jets. Handles waves breaking over the bag.
- IPX7 — submersible to 1 metre for 30 minutes. Adequate for most capsize scenarios.
- IPX8 — submersible beyond 1 metre continuously. Rated for diving and extreme conditions.
For kayaking and SUP, aim for IPX7 or above for anything protecting electronics. IPX4 is adequate for clothing storage where dampness is acceptable but soaking is not.
How to Pack a Dry Bag Properly
Step 1: Line the Inside (Optional)
For extra security on expensive electronics, place items in a small zip-lock bag before putting them in the dry bag. Belt and braces.
Step 2: Load from the Bottom
Place heaviest items at the bottom. This lowers the centre of gravity when the bag is stored in your boat, reducing the chance of it tipping and the roll-top opening under gravity.
Step 3: Squeeze Out Air
Before rolling, press the sides of the bag together to expel excess air. A bag full of air takes up more space and is buoyant (which sounds good but actually means it floats away from you in a capsize).
Step 4: Roll at Least Three Times
The roll-top seal is only effective with three or more folds. Each fold compresses the fabric together and eliminates gaps. Four rolls is better than three. Do not be lazy about this — a two-roll closure is not waterproof.
Step 5: Clip the Buckle
The buckle stops the roll unravelling but does not itself create the waterproof seal — that is the rolled fabric. The buckle is a security backup, not the primary closure.
Step 6: Clip to Something
Use the D-rings to clip the bag inside your cockpit, to deck bungees, or to your buoyancy aid. An unclipped dry bag that floats away after a capsize is useless regardless of how waterproof it is.
Dry Bags for Different Paddling Activities
Flat Water SUP
A deck bag with a dry pouch inside is usually sufficient. Capsizes on flat water are gentle — you slide off rather than being rolled by waves. A 5-10L dry bag for phone and keys, clipped under the bungees, covers most flat water paddlers.
River Kayaking (Mild to Moderate)
A 20L roll-top dry bag inside the rear hatch for spare clothes, plus a phone pouch on your buoyancy aid. Knowing how to safely exit a kayak is essential before venturing onto moving water. Capsizes happen more on rivers — eddies, small rapids, and overhanging branches all catch people out. Everything must be submersion-rated.
Sea Kayaking
The most demanding environment. Salt water corrodes everything, conditions change rapidly, and capsizes in cold water are dangerous. Use the best quality dry bags you can afford (Sea to Summit Hydraulic or OverBoard Pro-Vis), carry safety equipment in a separate small bag on your person, and pack a full change of warm clothes in case you are separated from your kayak.
Canoe Touring
Multi-day canoe trips on UK rivers and canals involve rain, splashing, and occasional capsizes at weirs or rapids. Large dry bags (40-60L) or dry barrels for camping equipment, plus smaller bags for daily access items. Canoes have more storage space than kayaks, so weight is less of a concern — prioritise durability over ultralight materials.
Caring for Your Dry Bags
After Every Use
Rinse with fresh water, especially after salt water use. Salt crystals in the roll-top fold area will damage the waterproof coating over time. Open the bag fully and turn it inside out to dry — storing a damp dry bag closed creates mould and degrades the fabric coating.
Avoid UV Exposure
Do not leave dry bags in direct sunlight when not in use. UV radiation degrades both PVC and TPU coatings, eventually causing cracking and loss of waterproofing. Store in a cool, dark place between uses.
Check the Seals
Before each season, fill your dry bag with air (roll and clip it shut with air inside) and submerge it in a bath or bucket. If air bubbles escape, you have a leak. Small punctures in PVC bags can be repaired with a bicycle puncture repair kit. TPU bags are harder to patch — if the fabric is failing, replace the bag.
Frequently Asked Questions
Are dry bags fully waterproof? Quality dry bags with welded seams and proper roll-top closures are fully submersible — rated to IPX7 or IPX8. Cheaper bags with taped seams or zip closures may be splash-proof (IPX4) but not submersion-proof. Always check the IPX rating if you need guaranteed protection in a capsize.
What size dry bag do I need for kayaking? A 5L bag for phone, keys, and wallet on short paddles. A 20L bag for a full change of clothes and lunch on day trips. 40-60L for overnight gear on multi-day trips. Most day paddlers find 20L is the sweet spot.
Can I use my phone through a dry bag? Not through a standard dry bag, but waterproof phone pouches (like the Aquapac TrailProof) have clear TPU windows that allow touchscreen operation. These are separate from your main dry bag and designed to keep your phone accessible while protected.
How long do dry bags last? A quality PVC or TPU dry bag lasts 3-5 years of regular use with proper care. UV exposure and salt water accelerate degradation. Check seals annually and replace when the fabric becomes stiff, cracked, or fails the submersion test.
Do dry bags float? A sealed dry bag with air inside will float briefly. However, this is not a safety feature — bags can be punctured, buckles can fail, and a floating bag drifts away from you in current or wind. Always clip your dry bag to your boat or person.