Sea to Summit
Sea to Summit Lightweight Dry Bag (20 L)
- Waterproof build: 5/10 How well its build keeps water out, from the published seams, closure and submersion claim.
- Weight for its size: 8/10 How much it adds to your pack for the space it protects.
Lowest price we found
£23.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 2 shopsKeeping a sleeping bag or spare layers dry inside a rucksack on wet UK hill trips
- Capacity
- 20 L
- Weight
- 91 g
- Seams
- Taped
- Closure
- Roll top
- Fabric
- 70 denier
Where to buy
Ultralight Outdoor Gear £23.99 In stock. Free delivery. 20 L price; Beluga colour £24.99. Free UK delivery over £15.
View at shop: Ultralight Outdoor GearSea to Summit £24 In stock. Delivery £4.50. 20 L price; Beluga Grey £25. Free delivery over £75.
View at shop: Sea to SummitPrices checked 2 Nov 2026 to 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Waterproof build
Estimate from maker's specs: seams, closure and water rating 5/10How well its build keeps water out, from the published seams, closure and submersion claim. 5: Does the job. Average for wild-camping gear.
Estimate from maker's specs
Weight for its size
From maker's figures 8/10How much it adds to your pack for the space it protects. 8: Clearly better than most.
91 g for 20 L is 4.6 g/L, in the 4.0–5.9 g/L band (Sea to Summit's figure; Ultralight Outdoor Gear lists 98 g, 4.9 g/L, the same band).
In short
Good for
- Keeping a sleeping bag or spare layers dry inside a rucksack on wet UK hill trips
- Colour-coded packing, in several colours
- Clipping to a rucksack, bike or boat by the D-ring when it will only get splashed
Strengths
- 91 g for 20 L, light for a 70D bag
- Recycled 70D nylon body with a PFC-free water-repellent finish
- White interior coating makes small items easier to find in poor light
- Oval base stops it rolling away and packs better
- D-ring at the buckle for lashing it down
- Seven sizes from 1.5 to 35 L
Weaknesses
- Not for submersion: Sea to Summit says it keeps water out only where the bag will not be under water
- Sea to Summit's page doesn't say how the seams are sealed (one UK shop says taped), so the waterproof build is an estimate, not a reviewed score
- Roll-top closure, so it is not the same as a welded paddling bag
- No reviews of the 20 L itself were found, so durability and ease scores are missing
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (5)
- Sea to Summit UK: Lightweight Dry Bag, 20 L size table
- Advnture: Sea to Summit Lightweight Dry Bag review (5 L tested, nearly a year of use; not used for a score)
- OutdoorGearLab: The Best Dry Bags, Sea to Summit Lightweight (5 L tested; not used for a score)
- Vertical Life: Sea to Summit Dry Bags, Lightweight set of 3 (3, 5 and 8 L; not used for a score)
- Tamarack Outdoors: Sea to Summit Lightweight Dry Bag (taped seams)