Lash to kayaks, bikes and 4WDs with confidence, or add a Dry Bag Sling (sold separately, 2023 model or newer, sizes 5L – 35L only) for comfortable hands-free carrying. Big River Dry Bags are a durable and abrasion resistant option that uses a strong 420D nylon fabric. If your idea of outdoor recreation involves rugged water sports like kayaking, canoeing, rafting, or motorcycle touring, they are the perfect storage bags to keep your gear dry. A white interior laminate affords greater visibility, and lash loops allow secure stacking or attachment to watercraft, motorcycles and other equipment. The hypalon non-wicking roll-top closure keeps water out, and the Field Repair Buckles can be replaced in seconds with just a Philips screwdriver. It also was designed with an oval base to save space when packing and prevent it from rolling away.
10000mm Waterproof
10,000 mm hydrostatic head — fully waterproof body fabric handles paddle sports, motorcycle rain, and rugged wet conditions.
6 Sizes
5L, 8L, 13L, 20L, 35L, 65L — from pocket-sized to week-long expedition storage.
Built Tough
Heavy-duty 420D ripstop nylon + triple-coated base — abrasion and puncture-resistant.
Roll-Top Closure
Hypalon non-wicking roll-top with Field Repair Buckles — reliable seal, replaceable buckles.
Field Repairable
Field Repair Buckles replaced in seconds with just a Phillips screwdriver.
Multi-Activity
Kayaking, canoeing, rafting, motorcycle touring, bikepacking, 4WD, snowmobile.
10000 mm Hydrostatic Head (NEW — WATERPROOF RATING)
The Big River's body fabric has a 10,000 mm hydrostatic head rating — same as the Big River Dry Backpack. Rating context:
- 1,500 mm = minimum "waterproof"
- 5,000 mm = waterproof for most rain
- 10,000 mm = waterproof for submersion (this product)
- 20,000 mm = fully waterproof for prolonged submersion
10,000 mm handles whitewater paddling, motorcycle rain, splashing waves, prolonged wet conditions. Per STS FAQ: "The body of the dry bag is waterproof (10,000 mm hydrostatic head)."
Heavy-Duty 420D Ripstop Nylon
Built from the same heavy-duty 420D ripstop nylon as the Big River Dry Backpack — much heavier and more durable than the 15D/20D fabrics used in sleeping bags and pillows. Ripstop weave prevents small tears from propagating.
Triple-Coated Base
The base has a triple coating for additional waterproof resistance and abrasion protection. This is the highest-wear area of any dry bag (it sits on rocks, in boat bilges, on motorcycle luggage racks), so the extra coating pays off over years of use.
Hypalon Non-Wicking Roll-Top Closure
The pack closes with a hypalon non-wicking roll-top:
- Hypalon = synthetic rubber, UV-resistant, chemically stable, durable
- Non-wicking = fabric doesn't absorb water via capillary action
- Roll-top = fold the top down 3-4 times and clip with the buckle. Folding creates a mechanical seal.
Field Repair Buckles (NEW — KEY FEATURE)
Patented Field Repair Buckles — replaceable in seconds with a Phillips screwdriver (no special tools, no sewing). Same buckle system used on the Big River Dry Backpack, Air Chair, and other STS products. STS sells replacement buckles separately.
POM Buckles (NEW — MATERIAL)
The buckles are made from POM (Polyoxymethylene) — also called acetal plastic. POM has:
- High stiffness
- Low friction (slider mechanism works smoothly)
- Excellent dimensional stability (doesn't deform under load)
- Good chemical resistance
Common in high-quality buckles, gears, and zippers. STS chose POM for its durability in harsh outdoor conditions.
White Interior Laminate
The interior is lined with a white laminate that reflects light — makes gear inside the bag much easier to find in low-light conditions (kayak cockpit, dusk, dark tent, motorcycle luggage compartment). Same feature as the Big River Dry Backpack.
Oval Base (NEW — DESIGN UPGRADE)
The Big River has an oval base (recently updated design feature) — provides two practical benefits:
- Prevents rolling — a round dry bag can roll away on a sloped boat deck, motorcycle rack, or tent floor. The oval base sits flat.
- Better packing — oval-based bags nest together more efficiently for transport and storage than round bags.
Multiple Lash Points & D-Rings
The bag has multiple lash points along the long axis plus double D-Rings — provides versatile attachment for:
- Securing to kayaks (deck rigging, spray skirt)
- Attaching to motorcycles (rack straps)
- Lashing to bikes (handlebar bags, frame bags)
- Mounting to 4WD roof racks
- Securing to whitewater rafts
- Snowmobile storage
Per STS: "Plenty of reliable attachment points with lash rails on the side to secure your Big River to your motorcycle, whitewater raft, bikepacking bike, 4x4 or snowmobile."
Low-Profile Grab Handles
The grab handles are intentionally low-profile to reduce snag resistance — important when loading/unloading the bag in tight spaces (kayak hatches, motorcycle luggage, raft compartments). High-profile handles catch on things.
Versatility: Hands-Free Carry Option
Dry Bag Sling Compatibility (NEW — ACCESSORY)
The Big River is compatible with the STS Dry Bag Sling (sold separately) — a detachable shoulder strap that converts the bag into a hands-free tote. Per STS: "The detachable Dry Bag Sling converts certain compatible dry bags to a hands-free tote. This ingenious design adds over-the-shoulder convenience to a dry bag equipped with a base attachment point."
Compatible sizes: 5L, 8L, 13L, 20L, 35L (NOT 65L — the 65L is too large for comfortable sling carry)
2023 model or newer required (older bags may not have the base attachment point)
This is a great cross-sell for SpokeX — shoppers buying the Big River + Dry Bag Sling get a complete portable storage system.
Awards (NEW SECTION TYPE)
The Big River has won three industry awards:
- Bikepacking — Buyer's Guide (industry recognition in bikepacking community)
- T3 — Approved (T3 is a UK tech/gear publication)
- Yachting World — Buyer's Guide (marine/sailing industry recognition)
Awards signal third-party validation — worth featuring in PDP copy as a trust signal.
Submersion Caveat (NEW — IMPORTANT LIMITATION)
Per STS FAQ: "The body of the dry bag is waterproof (10,000 mm hydrostatic head). However, avoid submersion since water can seep through the roll-top closure of any dry bag."
Important distinction: The FABRIC is fully waterproof, but the roll-top closure is not a guaranteed seal against submersion. For paddle sports where the bag might briefly go underwater (capsize, wave crash), this is usually fine. For prolonged underwater use (scuba, free diving), consider a hard case or specialized submersible bag.
5L / 8L / 13L / 20L / 35L / 65L (6 Sizes)
Six sizes for different use cases:
- 5L — small essentials (phone, wallet, keys, snacks)
- 8L — day-hike essentials (rain gear, lunch, water)
- 13L — overnight trip (clothes, sleeping bag liner)
- 20L — 2-3 day trip (clothes + sleeping bag)
- 35L — week-long trip (most popular bikepacking size)
- 65L — expedition (full gear load)
Best Use
Activity
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Paddle Sports (kayaking, canoeing, rafting), Motorcycle Touring, Bikepacking, 4WD, Snowmobile, Sailing/Boating, Wet-Weather Activities
Materials & Construction
Fabric
100% Nylon (420D ripstop, heavy-duty, non-PFAS laminate, UV resistant)
Buckles
100% POM (Polyoxymethylene / acetal plastic)
Closure
Hypalon non-wicking roll-top
Base
Triple-coated oval base (prevents rolling + packs better)
Seam Construction
Waterproof, double-stitched, reinforced, tape-sealed seams
Interior
White laminate (reflects light for gear visibility)
Hydrostatic Head
10,000 mm (fully waterproof body fabric)
Dimensions & Weight (by size)
| Measurement |
5L |
8L |
13L |
20L |
35L |
65L |
| Weight |
4.8 oz / 136 g |
5.6 oz / 159 g |
6.8 oz / 193 g |
8.8 oz / 249 g |
10.9 oz / 309 g |
15.3 oz / 433 g |
| Height (Top Rolled 3×) |
12.72 in / 32.3 cm |
14.72 in / 37.4 cm |
17.32 in / 44 cm |
18.94 in / 48.1 cm |
23.07 in / 58.6 cm |
28.27 in / 71.8 cm |
| Base L × W |
5.6 × 6.6 in |
6.5 × 7.6 in |
7.9 × 8.7 in |
9.6 × 10.4 in |
11.1 × 12.5 in |
13.9 × 15.0 in |
| Dimensions |
6 × 7 × 13 in |
6 × 8 × 15 in |
8 × 9 × 17 in |
10 × 10 × 19 in |
11 × 12 × 23 in |
14 × 15 × 28 in |
Performance (STS scales)
Weight Class
Heavyweight (purpose-built for rugged use, not ultralight)
Usage Class
Rugged Storage (the heaviest-duty tier on STS scale)
Compatibility
Attachment Points
Multiple lash rails along long axis + double D-Rings
Compatible Accessories
STS Dry Bag Sling (sold separately) — for sizes 5L-35L only
Compatible Activities
Kayaks, canoes, rafts, motorcycles, bikes, 4WDs, snowmobiles, sailboats
Inside Pockets
None (pack items in stuff sacks for organization)
Profile
Brand
Sea to Summit (Australian outdoor gear, founded 1994)
Category
Dry Bag / Waterproof Bag / Paddle Sports Storage
Activity
Paddle sports, motorcycle touring, bikepacking, sailing, 4WD, snowmobile
Season
Year-round (all seasons — handles all weather conditions)
Cleaning
Rinse with fresh water after exposure to salt, mud, sand, or dirt. For tougher grime, use a mild soap and a soft brush. Avoid harsh detergents that can degrade the waterproof laminate. Air dry completely before long-term storage. Do not machine wash or tumble dry — can damage the seam sealing, hypalon roll-top, and POM buckles.
Drying
Open fully and hang or stand upside down in a well-ventilated area. The 420D nylon dries slowly due to its thickness — allow extra time. For long-term storage, ensure the bag is completely dry before storage to prevent mildew and odor.
Roll-Top Closure Care
Periodically inspect the hypalon roll-top for cracks, cuts, or stiffness. Hypalon is durable but can degrade with years of UV exposure. To maintain water resistance:
- Roll the top down at least 3-4 times (more for submersion-prone applications)
- Ensure the buckles are fully clipped and tensioned
- Clean the buckle tracks of any debris or salt
- Inspect the fold area for wear or pinholes
- Avoid submersion per STS FAQ — water can seep through any roll-top closure if submerged
Field Repair Buckle Replacement
POM buckles can be replaced in seconds with a Phillips screwdriver:
- Use a Phillips screwdriver to remove the screw/pin on the buckle
- Slide the old buckle off the webbing
- Slide the new buckle onto the webbing
- Re-insert the screw/pin and tighten
No special tools, no sewing. STS sells replacement 20mm POM buckles separately. Carry a spare set on extended trips for emergency repairs.
Seam Sealing Inspection
The Big River uses waterproof, double-stitched, reinforced, tape-sealed seams. Periodically inspect the seams for:
- Peeling or delaminating seam tape
- Stitching failures (broken threads)
- Punctures or cuts near seams
If a seam starts to fail, repair with STS seam sealer or contact STS warranty service.
POM Buckle Care
POM (Polyoxymethylene) buckles are highly durable but can wear over years of heavy use. Periodically inspect for:
- Cracks in the plastic (especially at stress points)
- Bent or broken screw/pin
- Worn webbing slots (where the webbing passes through)
If a buckle wears out, replacement is simple (see Field Repair Buckle Replacement above).
Triple-Coated Base Inspection
The triple-coated base takes the most abuse — sits on rocks, in boat bilges, on motorcycle racks. Periodically inspect for:
- Coating wear or peeling
- Punctures from sharp objects
- Color fading from UV exposure
Small coating failures can be repaired with STS repair patches or silicone/PU seam sealer.
Puncture Repair
Small punctures or cuts in the 420D nylon fabric can be repaired with STS repair patches or any heavy-duty silicone/PU repair tape. Clean and dry the area, apply the patch, and allow to cure for 12–24 hours before use. Larger tears or seam failures may need professional repair — contact STS warranty service.
Long-Term Storage
Store dry, clean, loosely rolled (not compressed), and out of direct sunlight. UV degrades the 420D nylon and the hypalon roll-top over time. For very long-term storage, consider stuffing with newspaper or rags to maintain shape and absorb any residual moisture. Store the POM buckles loosely clipped (not under tension).
Activity-Specific Tips
- Paddle sports: Roll the top at least 4 times before getting in the kayak/canoe/raft. The 10,000 mm waterproof rating handles splash and brief submersion; the roll-top closure is the primary defense against water entry.
- Motorcycle touring: Use the lash rails and D-rings to secure to the bike's luggage rack. The 420D fabric handles highway vibration and weather exposure well.
- Bikepacking: Most popular bikepacking size is 35L — fits in front roll-top bags or larger frame bags. Multiple lash points work with various bike mounting systems.
- Sailing/Yachting: The UV-resistant 420D nylon is well-suited to marine environments. Rinse with fresh water after salt exposure.
- Snowmobile: Cold-flexible hypalon roll-top + POM buckles work in extreme cold.
