SL-C610 50L Welded Waterproof Floating Duffel Backpack with Airtight Zipper, IPX7

Sealock manufactures and supplies the SL-C610 50L Welded Waterproof Floating Duffel Backpack with Airtight Zipper for watersports, expedition, moto-touring and travel brands, and for outfitting, rental and crew-kitting programs. The bag measures 53 × 34 × 29 cm, holds 50 L and weighs 0.8 kg. The shell is TPU-coated fabric joined entirely by high-frequency welding; shell panels, base, strap anchors, handle anchors and lash tabs are all fused rather than stitched.

The main compartment is closed by a vertical airtight zipper running down the centre of the back panel, between the shoulder straps. Placing the opening on the back panel keeps it against the wearer in backpack mode and on top in duffel mode, away from spray and abrasion on the front face. The zipper carries welded TPU flanges either side of the teeth and a moulded end-stop lock at the base that holds the slider in the fully closed position. A capped inflation and purge valve sits on the lower back panel.

Protection is rated IPX7: the closed bag withstands temporary immersion and is verified by a two-hour submersion test with no ingress. It is designed for kayak and SUP decks, raft and boat use, beach landings, river crossings and open-water use where the bag may go in the water, and with air added through the valve it floats as a buoyant dry bag. It is not a dive bag, is not intended for sustained submersion at depth, and is not a personal flotation device or life-saving equipment.

At a Glance

• Airtight zipper, IPX7 — the main opening is an airtight zipper with welded flanges and an end-stop lock, closing a fully welded TPU shell; rated for temporary immersion and verified by a two-hour submersion check.
• Inflatable floating dry bag — a capped two-way valve on the lower panel lets the user add air so the closed bag floats high on the surface with its contents dry, or vent air so a soft load compresses down for a hatch, rack or car boot.
• Backpack or duffel carry — padded shoulder straps clip on at the top and adjust on webbing at the base; with them removed, webbing handles at the top and bottom carry the bag as a duffel.
• Shock-cord lash panels on three faces — elastic cord laced through welded tabs runs down both sides and across the lower front for a wet jacket, a sleeping mat, a paddle leash or a pair of sandals outside the sealed volume.
• 0.8 kg for 50 L — a single-layer welded TPU shell without internal frame or lining keeps the empty weight low for a bag this size.

Airtight Zipper and Inflation Valve

The airtight zipper uses interlocking moulded teeth sealed by a continuous TPU profile rather than a coated coil, which is what lets a zipper closure reach an immersion rating. The flanges either side of the teeth are welded into the back panel, so the zipper line carries no stitching. The end-stop at the base is a moulded lock the slider parks into; without it, an airtight zipper left a few millimetres short of fully closed passes visual inspection and still leaks. A pull tab sized for gloved hands is fitted to the slider.

The valve is a capped two-way port on the lower back panel. With the airtight zipper closed, the user can blow air in through the valve to inflate the bag, turning it into a floating dry bag that rides high on the surface — easy to see in the water, easy to grab from a kayak or the shore, and able to carry clothing, food or electronics across a river or alongside a paddler without anything getting wet. Opened the other way, the same valve vents trapped air so a soft load can be pressed down to a smaller volume for a hatch, a rack or a car boot. Replacing the cap holds whichever state the user has chosen. The valve is sealed by its cap and is included in both the IPX7 submersion test and the air-retention test.

Floating use is about protecting and recovering gear, not people. SL-C610 is not a personal flotation device, is not certified as buoyancy or life-saving equipment, and should never be relied on to support a person in the water.

Detachable Straps and Two Carry Modes

The shoulder straps are padded, bound in TPU and contoured to the shoulder. Each clips on at the top through a side-release buckle mounted on a welded tab and adjusts on webbing at the base through a ladder lock, also on a welded anchor. Released at both ends, the straps come off entirely — for a boat hatch or a luggage belt where loose straps snag, or for floating use where trailing straps can tangle.

For duffel carry, webbing handles are fitted at the top and bottom of the back panel, and a pair of long webbing handles runs across what becomes the top face when the bag is laid horizontally. The bag is symmetrical enough to sit flat in either orientation, and the airtight zipper faces upward in duffel mode, where it is easiest to reach. In the water, the same handles give a firm grab point for pulling the floating bag back aboard.

External Lash Panels

Shock cord is laced through welded tabs down both side panels and across the lower front face. The cord holds a wet jacket, a sleeping mat, a pair of sandals, a spare paddle leash or a rope bag against the shell and keeps wet or sandy items out of the sealed volume. The lash points also serve as tie-off points for securing the bag to a kayak deck or a SUP with a short leash. Because every tab is welded to the shell, the lash panels add attachment without adding a single needle hole to a bag rated for immersion.

Engineering Specifications

Brand	Sealock Outdoor Gear
Model	SL-C610
Category	Welded waterproof floating duffel backpack
Construction	High-frequency welded shell, welded strap, handle and lash anchors; no stitched structural seams
Waterproof structure	Fully welded TPU shell, airtight zipper with welded flanges, capped inflation / purge valve
Closure	Vertical airtight zipper on the back panel with moulded end-stop lock
Protection level	IPX7 — temporary immersion; verified by 2-hour submersion test
Flotation	Floats when closed; buoyancy increased by inflating through the valve (gear flotation only, not a PFD)
Dimensions	53 × 34 × 29 cm (L × W × H)
Capacity	50 L
Weight	0.8 kg
Carry modes	Backpack with detachable padded straps; duffel with top, bottom and cross-face webbing handles
External attachment	Shock-cord lash panels on both sides and lower front
Stock colours	Yellow, orange; custom Pantone available
Country of origin	Guangdong, China (secondary facility: Ho Chi Minh City, Vietnam)

Material Specifications

Component	Material	Purpose
Main shell	0.45 mm TPU-coated polyester	Weldable waterproof body, abrasion-resistant, stays flexible in cold water
Main closure	Airtight zipper with moulded teeth, welded TPU flanges, end-stop lock	Immersion-rated seal at the only opening
Inflation / purge valve	Moulded two-way valve with screw cap, welded flange	Inflates the bag for flotation or vents air for compression; sealed when capped
Shoulder straps	EVA padding with TPU binding	Padded carry that sheds water and dries quickly
Strap hardware	POM side-release buckles and ladder locks	Tool-free strap removal; no corrosion in salt water
Handles	Polyester webbing on welded TPU anchors	Duffel carry, hatch extraction and in-water recovery without shell perforation
Lash panels	Elastic shock cord through welded TPU tabs	External stowage for wet or bulky items and deck tie-off

Functional Specifications

Feature	Description
Main opening	Vertical airtight zipper down the back panel; faces upward in duffel mode
Zipper lock	Moulded end-stop parks the slider in the fully sealed position
Flotation	Inflate through the valve and the closed bag floats as a buoyant dry bag; contents stay dry on the surface
Compression	Vent through the same valve to press a soft load down for packing
In-water recovery	Bright stock colours and webbing handles make the floating bag easy to spot and pull aboard
Backpack carry	Padded straps, clip-on at top, webbing-adjusted at base
Duffel carry	Top and bottom webbing handles plus cross-face carry handles
Strap removal	Both straps detach completely for hatches, racks, luggage belts and floating use
External stowage	Shock-cord lash panels on both sides and lower front
Weather and water	IPX7 — rain, spray, wave wash and temporary immersion
Care	Rinse with fresh water after salt or sand exposure; dry open; lubricate the airtight zipper periodically

Customization / OEM Specifications

Item	Options
Colour	Yellow and orange in stock; Pantone-matched shells, contrast base panel, matte or gloss finish
Size and capacity	Scaled patterns from roughly 30 L to 90 L on the same welded platform
Material	TPU-coated polyester, heavier TPU, PVC tarpaulin or recycled TPU
Closure	Airtight zipper length and position, or a waterproof zipper variant at a lower price point and IPX6 rating (not suited to floating use)
Valve	Inflation / purge valve as standard, oral-inflation tube, high-flow valve, or deleted
Carry system	Padded hip belt, sternum strap, shoulder strap for single-shoulder carry
External features	Additional lash points, D-rings, leash attachment point, reflective trim, clear ID window
Interior	Welded internal pocket, removable divider, key tether
Branding	Screen print, silicone print, welded TPU patch, reflective print, shell embossing

Sealock has run OEM and ODM programs for outdoor, watersports and travel brands for over 20 years, and the most demanding requirements on this platform can be met. Development does not have to begin from an existing model: our engineering team regularly builds products from scratch off a customer's sketch, a physical sample, or nothing more than a target specification sheet, taking the project through structural design, pattern development, welding-parameter validation, immersion and air-retention testing, and pilot production. Both our high-frequency welding capability and our in-house sewn production line are professional operations in their own right, so hybrid constructions — a welded waterproof body with a sewn carry system or organiser — are fully supported. Ground-up custom development carries a longer lead time than a modification of an existing platform, and we will state that timeline at the quotation stage rather than after tooling has started.

Packaging Specifications

Individual packing	Recyclable PE polybag; straps detached and packed inside, zipper left partly open to protect the seal
Retail option	Hang tag, IPX rating, flotation-use and zipper-care label, printed insert card or full-colour box
Carton	Standard 5-ply export carton, 20 pcs per carton (subject to final configuration)
Carton printing	Customer artwork, one or two colours, or plain kraft
Barcode	EAN / UPC applied to polybag, hang tag or box as instructed
Hang tag	Customer-supplied artwork, string or plastic fastener
Shipping marks	Customer format printed or labelled on two carton faces
Palletisation	Standard export pallet, stretch-wrapped, corner-protected, on request

Recommended Use

Scenario	Suitable
Kayak, canoe and SUP touring	✔
Floating gear bag carried alongside a paddler or across a river	✔
Rafting and boat trips	✔
Beach landings and river crossings	✔
Motorcycle touring, strapped to a rack or seat	✔
Expedition and camping gear transport	✔
Travel luggage in wet climates	✔
Rental fleet and crew kit issuing	✔
Scuba diving or sustained submersion at depth	✘
Use as a life jacket, PFD or rescue flotation for a person	✘
Loads above 15 kg carried for long distances	✘
Hard-edged cargo without internal padding	✘

IPX7 covers temporary immersion, not depth. SL-C610 will survive going overboard, sitting in a flooded bilge or being dragged through a river crossing, and inflated through its valve it floats as a buoyant dry bag — but it is not a dive bag. Its flotation is for keeping gear on the surface and dry, not for supporting a person, and it is not certified as a personal flotation device or life-saving equipment. The load limit reflects the carry system: the stock straps have no hip belt, so heavy loads sit entirely on the shoulders.

Quality Inspection Standards

Test	Standard
Submersion test	Closed bag with valve capped, submerged for 2 hours or more, no water ingress
Air retention test	Bag inflated via the valve and held; no pressure loss at zipper, valve or seams
Flotation check	Inflated bag at rated load floats on the surface with zipper and valve above the waterline
Weld seam peel and shear	Destructive sampling against internal welded-seam strength standards
Airtight zipper cycling	Repeated open–close cycles with seal re-verified afterwards
Strap and handle anchor pull-off	Welded anchors tested to internal force limits
Loaded drop test	Repeated drops at rated load, no weld separation or hardware fracture
Abrasion resistance	Martindale cycling on shell and base panel
Salt spray test	Zipper, valve and buckles, corrosion and function retention
Low-temperature flex	Shell and zipper tested for cracking and stiffness at reduced temperature
Colour fastness and colour difference	Rubbing and light fastness; ΔE checked against approved lab dip for each colour

Quality control runs across three gates. IQC screens incoming TPU-coated fabric, airtight zippers, valve assemblies, webbing and hardware against approved samples, with lot-level checks on coating thickness, zipper profile and colour difference. IPQC monitors welding temperature, pressure and dwell time at every station in real time and pulls destructive seam samples at set intervals. OQC performs the air-retention check and the submersion test on every carton lot, with the valve capped as it would be in use.

Buyers can reproduce our result at incoming inspection: close the airtight zipper fully into its end-stop, cap the valve, place a sheet of absorbent paper inside, and submerge the bag for two hours. The paper should come out dry. For the air-retention check, inflate the closed bag through the valve, recap it and leave it standing; it should hold its shape without softening. The most common false failure in either test is a zipper left a few millimetres short of the end-stop, so check the slider position first. Third-party inspection by SGS, QIMA or a buyer-nominated agency can be arranged at any stage of production.

Product Highlights

Feature	Advantage
Airtight zipper with end-stop lock	Immersion-rated closure that cannot be left almost-shut by mistake
Inflatable floating body	The bag stays on the surface with its contents dry, and is easy to spot and recover
Two-way valve	The same port inflates for flotation or vents for compression, depending on the day
Back-panel zipper position	Opening sits against the wearer or faces up, away from spray and abrasion
Fully detachable straps	No loose webbing to snag in a hatch, on a luggage belt or in the water
Welded lash tabs	External stowage and deck tie-off on three faces without a needle hole in an IPX7 shell
0.8 kg empty	Low base weight for 50 L, which matters on a kayak or a motorcycle

Printing & Logo Options

The front panel is a flat, uninterrupted print area above the lower lash panel. Screen printing suits one- to three-colour marks at volume and is the standard on this shell. Silicone print gives a slightly raised, abrasion-resistant finish. A welded TPU patch produces a tonal, dimensional mark applied in the same process as the rest of the bag. Reflective print is available for moto, night-use and on-water visibility, and the shell can be embossed during welding. Logo customisation is available from the 300-piece MOQ, and webbing, buckles, shock cord and the valve cap can all be colour-matched.

OEM / ODM and Wholesale

SL-C610 is available as a stock platform for wholesale and as a development base for OEM and ODM programs. Minimum order quantity is 300 pieces per colour, with FOB terms from Guangdong. Sample lead time is 7–15 days for a stock unit with applied branding, and longer where a new size, closure or material is required. Sealock has built waterproof and welded gear for over 20 years, operates facilities in Dongguan, China and Ho Chi Minh City, Vietnam, and produces for brands including OSPREY, STANLEY, snow peak, MUJI and DESCENTE. The same specification can be produced from either origin.

Related Products

Buyers specifying a waterproof duffel range usually compare this model with the SL-C594 55 L airtight-zipper waterproof duffel, the SL-C893 70 L camo waterproof duffel and the SL-C878 20 L waterproof travel and gym duffel. For a floating backpack at daypack size, see the SL-E978 38 L floating dry backpack; for packing inside it, the SL-P1082 vacuum compression packing bag; and for rack-mounted moto touring, the SL-E984 55 L three-way motorcycle bag and the SL-C807 motorcycle tail bag.

FAQ

What is the waterproof rating?

IPX7. With the airtight zipper fully closed into its end-stop and the valve capped, the bag withstands temporary immersion, verified by a two-hour submersion test on every production lot. It is suitable for kayaks, rafts, boats, river crossings and open-water use where the bag may go in the water. It is not a dive bag and is not rated for sustained submersion at depth.

Does it float, and can it be used as a floating dry bag?

Yes. Closed, the bag floats on its own; inflated through the valve, it rides higher on the surface with more buoyancy and its contents stay dry. That makes it suitable as a floating gear bag — carried alongside a paddler, pushed across a river, or recovered after going overboard — and the bright stock colours make it easy to spot. It is gear flotation only: it is not a personal flotation device, is not certified as life-saving equipment, and must not be relied on to support a person in the water.

What does the valve do?

It is a two-way inflation and purge valve. With the zipper closed, blow air in to inflate the bag for floating use, or open the cap and press the bag down to vent trapped air for a smaller packed volume. Recap to hold either state. The valve is sealed by its cap and is included in both the submersion and air-retention tests.

Why is the zipper on the back panel?

In backpack mode it sits against the wearer, away from spray and abrasion on the front face. In duffel mode and when floating it faces upward, above the waterline and easy to open. A front-mounted zipper would be exposed to wave wash on a kayak deck and to scraping when the bag is dragged.

Can the shoulder straps be removed?

Yes. Each strap releases at the top through a side-release buckle and at the base through a ladder lock, and comes off completely. Without them the bag carries as a duffel on the top, bottom and cross-face handles, with no loose webbing to snag in a boat hatch, on an airport belt or in the water.

What colours are available?

Yellow and orange are stock colours, both chosen for visibility on the water. Custom Pantone-matched shells, contrast base panels, and matte or gloss finishes are available from the 300-piece MOQ per colour, with colour difference checked against an approved lab dip at IQC.

Can we put our logo on it?

Yes, from the 300-piece MOQ. Screen print is standard; silicone print, welded TPU patch, reflective print and shell embossing are all available. Webbing, buckles, shock cord and the valve cap can be colour-matched to the brand.

How do we look after the airtight zipper?

Rinse it with fresh water after salt or sand exposure, dry the bag with the zipper open, and apply zipper lubricant periodically. Always run the slider fully into the end-stop when closing — an airtight zipper left a few millimetres short looks closed and still leaks, and will not hold air for floating use. A zipper-care label can be added to the retail packaging.

Can you make it in a different size?

Yes. The welded platform scales from roughly 30 L to 90 L, and PVC tarpaulin or recycled TPU can replace the stock shell. A waterproof-zipper version rated IPX6 is possible at a lower unit cost, but it will not hold air and is not suitable for floating use.

What is the minimum order quantity and lead time?

MOQ is 300 pieces per colour, FOB Guangdong. Samples ship in 7–15 days for stock units with applied branding; a new size, closure or material extends that. Bulk lead time depends on order size and season and is confirmed at order placement. The same specification can be produced in China or Vietnam, and third-party inspection by SGS, QIMA or a buyer-nominated agency can be scheduled at any stage.

Request a Quote

YiFuLong Outdoor Gear Co., Ltd. (Sealock)
Email: info@sealock.com.hk
Tel / WhatsApp / WeChat: +86-13632981825

Send us your target colour, capacity, branding method and annual volume, and we will come back with a quotation, a lead time and a sample plan for the SL-C610 welded waterproof floating duffel backpack.