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Wet trails don't have to mean wet gear.

The Sea To Summit Ultra-Sil Dry Sack is made with with siliconized Cordura to make it incredibly light, durable, and waterproof. Bring it along when you're backpacking or climbing, when you need to protect your gear from wet weather without taking on additional weight. Translucent for easy packing and identification, the Ultra-Sil Dry Sack features a slippery finish so it slides easily into your backpack.

  • All seams are double-stictched and taped to prevent leakage
  • Non-wicking Hypalon roll-top closure includes sitffeners at the top for a better seal
  • Suitable to keep contents dry in wet situations, but submersion is not recommended

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Sea To Summit Ultra-Sil Dry Sack

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Here's what others have to say...

Unanswered Question

I'm thinking of creating my own backpack with stuff sacks. I would like to use a 20 liter for the main body, and then use two smaller ones for the smaller gear. I need to have lightweight, durable and as waterproof as possible. Any suggestions?

Unanswered Question

What size would work best for a XL Mountain Hardwear Kelvinator down jacket w/hood? I don't like the built in one w/zipper so need something else. thanks, Rob

4 5

Love the colors

  • Familiarity: I've used it once or twice and have initial impressions

I got the berry one to use for a laundry/dirty clothes bag while travelling. It is lightweight and a good size bag and the rolldown top seals andy stink from dirty clothes away from your nose and contaminating the clean clothes.

1 5

waterproof but not very durable

  • Familiarity: I've put it through the wringer

They are waterproof and lightweight which is great, however they are not very rugged. I bought a few for a motorcycle trip to go with the standard ones I already had. They were inside my aluminum panniers the whole trip and many of them had holes in them from rubbing against the panniers. The standard bags help up fine. I will be throwing out 3 and replacing them with the regular ones as I cannot have holes and be constantly repairing them.

Great camera protection

Great camera protection

All our gear was kept in these bags. Great insurance when crossing numerous rivers and filming along river beds

5 5

Awesome for backpacking

  • Familiarity: I've put it through the wringer

These bags are great for keeping your stuff dry. I use one of these to keep my extra clothes and sleeping bag dry, and I don't worry about having a pack cover. It has yet to fail me, even after falling into a river during a ford.

For my lens

For my lens

I use it for winter photography trekking to keep my lens dry

5 5

Works Great!

  • Familiarity: I've used it several times

Used these on my last kayaking adventure and they worked great! Light weight and thin so great for storing when not using them. Kept all my clothes/gear dry while kayaking all day. Durable fabric!

5 5

20L - Love it

Whether I am flyfishing, going on a day hike, backpacking, canoeing, or snowshoeing, I pack everything I need dry in this. I believe it works better than a pack cover in most circumstances, especially flyfishing because I can't find a pack cover that would do a better job than this bag. I simply stuff anything I need to keep dry inside. For backpacking I can fit all my cloths and sleeping bag inside, and not have to worry about them getting wet if it starts raining, or I happen to fall into the river.

It is also very durable and well stitched and seamed. I would highly recommend this. It has lasted several years with no signs of wear and tear.

5 5

This bag rocks!

Whoa ! These Ultra-Sil bags are super light! Upgrading some older ripstop nylon bags in some of my backpacking gear. What a weight difference & waterproof too.Amazing the tech that's used now compared to 10years ago.

Would this work well as a bear bag?

Would this work well as a bear bag?

Best Answer Responded on

Joseph - I think so. The waterproof coating will keep your items dry in the rain or snow and the Cordura fabric is reasonably bomber, so you should be able to load this up without fear of breaking it under the weight.

Responded on

I have used as such in trip to Colorado last summer no issues.

3 5

Size listed is misleading

I ordered the 1 liter size, and discovered that the volume and dimensions listed refer to the bags open size, not its closed size. In the case of the 1 liter, once you roll the lid down its interior volume becomes more like 0.5 liter.

Responded on

I agree. I also got the 1L and it seems to only be max 1L when open. Although the model I received was of the envelope type. It lays flat like an envelope rather than a cylinder. When rolled up can closed it is rather small, and in fact sucks in air. I'm choosing to return mine soon.

4 5

So Far So Good

  • Familiarity: I've used it once or twice and have initial impressions

I used the 2L sack for the first time today on a kayaking trip. It kept everything dry as a bone even when it sat in a puddle for a few minutes.

It was the perfect size to carry two sets of keys, wallet and cell phone.

I probably won't continue to use it on the water, though, because the fabric is really lightweight and I don't have confidence it would stay waterproof if the boat flipped and it was completely submerged.

5 5

Love Thes

I've used these bags for several years - had no problems with leaking. Last a long, long time with moderate care. I wouldn't expect gear in these to stay dry if immersed. However, I've used these as bear bags in the rain. So far, so good.

5 5

Great for backpacking!

I use these for everything! I recently went backpacking and everything went into a Sea to Summit dry sack. I used the 13L for my tent (Kelty Salida 2) and 8L for my sleeping bag, although after compressing it down in the bag, my tent ended up smaller than my sleeping bag! I've used various other sizes for other gear, clothes, and food. These are very thin (lightweight) but seem to be pretty durable and definitely kept everything dry during several days rain.

Can you tell me if the 2L and 4L have round...

Can you tell me if the 2L and 4L have round bottoms?

Responded on

It seems to be random as to what size you get--if you get a round one or an envelope one.
If you get the STS Ultra-Sil *Nano* Dry Sack they are all cylinders.

I want to get one of these. Which size...

I want to get one of these. Which size would best fit a kelty cosmic 20 degree down bag? Thanks!

Best Answer Responded on

I'd go for the 8L to be on the safe side. If the sleeping bag compresses smaller than 8L you can always roll the excess dry-sack material up into the top. I use a 20L model to carry my 40 degree bag, sleeping pad, base layers, insulating layer, beanie, and gloves, and I still have a little extra room in the top, and it still fits horizontal across the bottom of my 80L backpack.

Will a 13L hold a tent and sleeping pad,...

Will a 13L hold a tent and sleeping pad, or should I go bigger?

Responded on

What tent and what sleeping pad? Those two items can vary in size.

5 5

Light and well made

I got a 2L sack to keep all my small backpacking gear in so it stays organized; works great. The Ultra-sil is noticeable thiner and lighter then the regular sea to summit stuff sacks, but feels plenty strong and they seem very well constructed.