Sea to Summit dry bag guide: lightweight waterproof storage for every adventure

Keep your gear dry without adding unnecessary weight

When you're heading into the outdoors, keeping essential gear dry is one of those small details that can make a huge difference. A wet sleeping bag, soaked clothing or damp electronics can quickly turn a great adventure into a miserable one.

That's where a quality Sea to Summit dry bag comes in. Whether we're organising clothing inside a hiking pack, protecting gear on a kayak or keeping equipment secure during a bikepacking trip, Sea to Summit offers dry storage options designed for different types of adventures.

At PAST Outdoors, we've selected several of our favourite Sea to Summit dry bags, including the tough Big River range and the incredibly lightweight Ultra-Sil range. The right choice depends on how much protection, durability and carrying capacity we need.

Why choose a Sea to Summit dry bag?

A dry bag is more than just a waterproof sack. The best designs make it easier to organise our equipment, protect valuable gear and make better use of limited pack space.

Sea to Summit dry bags are particularly useful because the range covers everything from lightweight backpacking storage to hard-wearing bags designed for demanding environments. We can choose a compact option for clothing and sleeping gear or step up to a more robust model when we're expecting serious abrasion, water exposure or rough handling.

For hiking and camping, dry bags can be used to separate clothing, sleeping systems, food and other essentials inside a backpack. They can also help us compress and organise equipment, making it easier to find what we need without unpacking the entire pack.

If you're planning a multi-day adventure, our multi-day hiking gear and packing guide is another useful resource for working out what belongs in your pack.

Sea to Summit Big River dry bag: built for rugged adventures

When durability is the priority, the Sea to Summit Big River Dry Bag is one of our go-to options.

The Big River is made from abrasion-resistant 420D nylon laminated with TPU, giving it the strength and waterproof protection needed for demanding outdoor activities. Its triple-coated base provides additional abrasion resistance, while double-stitched and tape-sealed seams help keep water out.

We particularly like the practical details. The waterproof roll-top closure is designed to stop moisture wicking into the bag, while the oval base helps prevent the bag from rolling around and makes packing more efficient. Multiple lash points also allow us to secure the bag to kayaks, bikes, motorbikes and 4WDs.

• 420D nylon with TPU laminate for strength and waterproofness
• Triple-coated base for increased abrasion resistance
• Waterproof, reinforced and tape-sealed seams
• Non-wicking roll-top closure
• Multiple lash points for versatile attachment
• White interior for improved visibility
• Oval base for better packing and stability
• Available in sizes from 5L through to 65L

The Big River is an excellent choice when we're looking for a Sea to Summit dry bag that can handle rougher conditions. It's particularly well suited to kayaking, rafting, canoeing, motorcycle touring, bikepacking and other adventures where gear may be exposed to water and abrasion.

Sea to Summit Big River dry backpack: waterproof carrying capacity

If we want the protection of a dry bag with the convenience of a backpack, the Sea to Summit Big River Dry Backpack takes the concept a step further.

Designed for activities where we need to carry our gear while staying protected from wet conditions, the Big River Dry Backpack combines a tough 420D nylon construction with an adjustable EVA foam harness, sternum strap and removable hipbelt.

The waterproof roll-top closure uses Field Repair Buckles, while the fully taped seams provide a reliable barrier against water. A triple-coated oval base adds durability and helps shed water when we're putting the pack down.

We also get grab handles and daisy-chain attachment points, making it easier to handle the pack or lash it securely to other equipment. The white interior TPU laminate reflects light, making it easier to see what's inside.

Available in 30L, 50L and 75L options, it's a particularly practical choice for water-based adventures, motorcycle touring and situations where a conventional backpack isn't enough protection.

Sea to Summit Ultra-Sil dry bag: lightweight protection for hiking

For lightweight adventures, our Sea to Summit Ultra-Sil Dry Bag range is hard to overlook.

The Ultra-Sil is designed for backpacking, cycle touring and travel where keeping weight down matters. Made from bluesign® approved Ultra-Sil 30D Cordura® nylon fabric, these bags provide waterproof storage while adding very little weight to our pack.

The weight savings are impressive. Depending on size, the individual bags weigh as little as 30 grams, with the 35L version weighing just 74 grams. That makes the Sea to Summit lightweight dry bag a smart option when we're carefully managing every gram in an ultralight pack.

• Extremely lightweight 30D Ultra-Sil Cordura® nylon
• Waterproof construction for protecting essential gear
• Semi-translucent fabric makes contents easy to identify
• Oval base helps prevent rolling
• Slippery finish makes packing and unpacking easier
• Non-wicking Hypalon roll-top closure
• Taped seams help prevent water entering
• PFC-free DWR finish
• Available from 3L to 35L

The translucent fabric is one of the features we find particularly useful. Instead of opening several bags to find a spare layer or piece of equipment, we can quickly see which bag contains what we're looking for.

That makes the Ultra-Sil an excellent choice for keeping clothing, sleeping accessories, electronics and other small essentials organised inside a hiking or travel pack.

Shop Sea to Summit Ultra Sil Dry Bags

Sea to Summit Ultra-Sil dry bag set: simple pack organisation

If one dry bag is useful, a selection of different sizes can make organising a backpack even easier. The Sea to Summit Ultra-Sil Dry Bag Set includes three bags in 3L, 5L and 8L sizes.

We can dedicate each size to a different category of gear. For example, a smaller bag can hold electronics or first-aid essentials, while larger bags can separate clothing, accessories or other equipment.

Because all three bags use the same lightweight Ultra-Sil construction, the set gives us a straightforward way to organise our pack without adding significant bulk or weight.

Each bag features the same semi-translucent fabric, oval base, slippery finish and PFC-free DWR finish found throughout the Ultra-Sil range. The result is lightweight, waterproof storage that works particularly well for hiking, bikepacking and travel.

Sea to Summit lightweight dry bag vs Big River: which should we choose?

Both ranges are designed to protect our gear, but they're aimed at slightly different priorities.

Feature	Ultra-Sil	Big River
Main priority	Low weight and packability	Durability and rugged use
Fabric	30D Ultra-Sil Cordura® nylon	420D nylon with TPU laminate
Best suited to	Hiking, backpacking, cycle touring and travel	Kayaking, rafting, touring and rugged adventures
Smallest size	3L	5L
Weight	From 30g	From 135g

In simple terms, if we're counting grams and want compact organisation inside a hiking pack, the Sea to Summit Ultra-Sil dry bag is an excellent choice. If we're expecting more abrasion, rough handling or regular exposure to challenging environments, the Big River offers a more robust construction.

For a broader selection, our compression dry sacks and waterproof storage collection is also worth exploring.

How to use a Sea to Summit dry bag when hiking

Dry bags work best when we use them as part of an organised packing system. Rather than placing every item into one large bag, we can divide our equipment according to how often we need it and how important it is to keep it dry.

• Clothing: Keep spare layers and underwear protected from rain and condensation.
• Sleeping gear: Protect clothing, sleeping accessories and other items we rely on at camp.
• Electronics: Use smaller dry bags for cameras, chargers, batteries and other sensitive equipment.
• Food: Keep snacks and selected food items organised and protected from moisture.
• Emergency equipment: Keep critical gear together so we can find it quickly when needed.
• Travel: Separate clean clothing and equipment inside a larger travel pack or duffle.

Using several smaller bags can also make it easier to move equipment between packs. The Ultra-Sil set is particularly useful for this approach, giving us three compact sizes for different categories of gear.

Why waterproof storage matters in Australian conditions

Australia offers an enormous variety of outdoor environments, from humid coastal tracks and tropical conditions to alpine areas and unpredictable weather. A dry bag gives us an extra layer of protection when we're dealing with rain, river crossings, spray or damp conditions.

Even when the forecast looks favourable, conditions can change quickly. Keeping our critical equipment inside waterproof storage means we're better prepared when the weather doesn't cooperate.

For lightweight hiking, a Sea to Summit lightweight dry bag is especially useful because we can gain waterproof organisation without adding much weight to our overall kit.

Explore more Sea to Summit gear at PAST Outdoors

Our Sea to Summit collection goes well beyond dry bags. We stock a broad range of Sea to Summit equipment for sleeping, shelter, cooking, hydration and outdoor travel, making it easy to build a complete kit around your next adventure.

If you're already using a Sea to Summit sleeping system, you may also enjoy our Sea to Summit Spark Down Sleeping Bag guide or our comparison of the Spark and Ascent sleeping bags.

Why shop for your Sea to Summit dry bag at PAST Outdoors?

At PAST Outdoors, we're not just interested in selling outdoor equipment. We're a family-owned Australian hiking, camping and travel business, founded in 2020 with a focus on helping more people get outside and enjoy the outdoors in all conditions.

Our team brings genuine outdoor experience to the gear we stock. PAST Outdoors was founded by Dave Parker, who spent almost 20 years conducting Special Operations in the Australian Army before combining that experience with an MBA and a passion for outdoor adventure.

We're also trusted suppliers to emergency services, government, military and outdoor education groups, so we understand the importance of dependable equipment when conditions become challenging.

Most importantly, our customers tell us that they value the combination of quality gear and knowledgeable service. Our Sea to Summit Ultra-Sil Dry Bag reviews include customers who have used the bags on the Kokoda Track and praised their ability to keep gear dry, while another customer highlighted Sea to Summit's consistent quality and the value of supporting a smaller local shop.

That's exactly what we aim to deliver: quality equipment, practical advice and a team that understands why the details matter.

Whether you need a rugged Sea to Summit dry bag for kayaking and touring, a Sea to Summit Ultra-Sil dry bag for lightweight backpacking or a versatile set for organising your hiking kit, we've got options to suit the way you adventure.

Frequently asked questions about Sea to Summit dry bags