How to Choose a Dry Bag for Boating: Sizes, Materials, and Features

Quick Answer

For most boating trips, choose a dry bag between 10 and 20 liters for day use, made from coated nylon or PVC with a roll-top closure. If you need to keep your phone handy and safe from splashes, add a waterproof phone case rather than relying on the bag alone.

When you're out on the water, the last thing you want is a soaked phone, soggy sandwich, or ruined change of clothes. A dry bag is the simplest way to keep your essentials protected from splashes, rain, and even an accidental dunking. But not all dry bags are the same, and picking the right one means thinking about how you'll use it, how much you need to carry, and what kind of water you'll encounter.

This guide breaks down the key decisions: size, material, and closure type. You'll also learn a few practical trade-offs that can save you money and frustration. Whether you're kayaking for an afternoon or heading out on a longer paddle, these rules will help you choose a dry bag that actually does its job.

Start with the Right Size

Dry bags come in a range of sizes, usually measured in liters. The size you need depends on what you're carrying and how long you'll be out. For a short paddle or a day trip, a 5- to 10-liter bag is enough for a phone, keys, a light jacket, and a snack. If you're bringing a full change of clothes, a towel, and a lunch, step up to a 20-liter bag. For overnight trips or carrying gear for more than one person, look at 30 liters and up.

A common mistake is buying a bag that's too large. A half-empty dry bag is harder to roll down properly, which can compromise the watertight seal. You want the bag full enough to roll the top three to four times. If you're often carrying just a few small items, a smaller bag or a waterproof phone case might be a better fit.

• Match the bag size to the amount of gear you actually carry, not the biggest option available.
• Leave enough space to roll the closure at least three times for a secure seal.

Materials Matter: Nylon, PVC, and Ripstop

The material of a dry bag determines its durability, weight, and flexibility. Lightweight nylon dry bags are easy to pack and great for casual use, but they may not withstand rough handling or sharp objects. PVC and heavier coated fabrics are more puncture-resistant and better for rocky shorelines or frequent use, but they weigh more and can be stiffer to fold.

Look for a bag with taped or welded seams, not just stitched seams, because water can seep through needle holes. A roll-top closure is the standard for a reason: it creates a reliable seal when folded correctly. Some bags add a buckle or clip to keep the roll in place, which is a handy feature if you're tossing the bag around.

• Check for welded or taped seams before buying—stitched-only seams can leak.
• If you'll be dragging the bag over rocks, choose a tougher material like PVC; for light use, nylon is fine.

Features That Make a Difference

Beyond size and material, small features can make a dry bag more convenient. A clear window or transparent panel lets you see what's inside without opening the bag. A shoulder strap or carry handle makes it easier to transport. Some bags have attachment points or D-rings so you can clip them to your boat or backpack.

For electronics like your phone, a dry bag alone isn't always enough. Even a well-sealed bag can be inconvenient if you need to access your phone frequently. A dedicated waterproof phone case, like the Smartphone Watertight Case, Large, lets you use your phone while it's protected from splashes and rain. It's a smart addition to any dry bag setup.

• Consider a clear window if you need to spot items quickly without unrolling the bag.
• Use a waterproof phone case for frequent phone access, and reserve the dry bag for bulkier items.

Decision Rules for Choosing a Dry Bag

• Size rule: For a day trip, choose 10–20 liters. For overnight or multi-day trips, choose 30 liters or more. Always leave room for a proper roll-top seal. If you're often carrying just a phone and keys, a smaller bag or a phone case is more practical.
• Material rule: Choose nylon for light, packable use. Choose PVC or heavier coated fabric for rocky environments or frequent rough use. Check for welded or taped seams to ensure watertightness.
• Closure rule: Always use a roll-top closure and roll at least three times before clipping. Avoid bags with only zipper closures unless they are rated submersible. If you need frequent access to your phone, add a waterproof phone case.

Products mentioned in this guide

• All Purpose Dry Sacks: Keep belongings dry when kayaking, camping in rainy weather, or traveling to adventurous climates with this three-pack of lightweight, highly weather-resistant dry sacks. Includes 2-, 4-, and 10-liter sizes to easily organize and protect all your gear, ranging from lifesaving layers to valuable cell phones and cameras. Each bag is crafted from soft, flexible rip-stop fabric. The multiple sizes let you match the bag to the trip, and the rip-stop fabric resists tears, so you can trust it for kayaking or rainy camping.
• Smartphone Watertight Case, Large: Protect your smartphone with the Outdoor Products Cell Phone Dry box. Its waterproof design keeps out dirt, sand and moisture so you can stay connected while working at a job site, floating down a river or camping. Made from shatterproof polycarbonate material, this case features an O-ring closure that ensures a watertight seal. For quick access to your phone on the water, this case offers a sealed, shatterproof option that complements a dry bag without needing to unroll it.

Who should choose what

Best for

• Day kayakers and paddleboarders who need to keep a phone, keys, and a snack dry.
• Boaters who want a lightweight, packable bag for occasional use in rainy conditions.

Not for

• Divers or snorkelers who need a rigid dry box that can withstand underwater pressure—a dry bag isn't designed for submersion beyond splashes.

Choosing the right dry bag for boating comes down to matching size, material, and features to your specific trip. Start with a 10- to 20-liter bag for most day outings, pick a material that suits your environment, and always roll the top properly. And when you need quick access to your phone, a waterproof case like the Smartphone Watertight Case, Large is a smart companion to any dry bag. With these rules in mind, you'll keep your gear dry and enjoy your time on the water.