Sea to Summit Ultra-Sil Compression Dry Sack

I’m a strong believer that my sleeping bag is perhaps the most important tool I have when in the woods. As such I want to protect it well. For years now I have been using a Sea to Summit eVent Compression Dry Sack to do just that. It has worked wonderfully for me. The stuff sack is completely waterproof with a roll-top closure. It is also very well designed to distribute the applied forces, so you can really compress it. I use the Medium size, and you can compress it from 14 litters to 4.5 litters without a problem.

The only downside to the stuff sack has been its weight. It is very robust, but that comes at a weight cost of almost 6 oz. Well, recently Sea to Summit came out with a new version called the Sea to Summit Ultra-Sil Compression Dry Sack, which addresses that problem. In the picture below you can see the new Ultra-Sil Dry Sack on the left and the older Event Dry Sack on the right.

The two stuff sacks are nearly identical. The main difference is that the Ultra-Sil Dry Sack comes in at 3.2 oz, almost half the weight of the Event version.

Now, the names of the two stuff sack are actually very misleading. The fact is that they are both made of eVent. The difference is that the Ultra-Sil version has the eVent base bonded to 30 denier nylon, while the previous eVent model has the eVent base bonded to 70 denier nylon. In short, both are eVent stuff sacks, but one is thinner than the other. The Ultra-Sil version also has thinner and slightly narrower straps and buckles.

I’ve used the new Ultra-Sil Dry Sack on several trips now, and I’ve been very happy with it, so I wanted to give you a closer look, as well as inform you that it is out there as an option.

The stuff sack has four buckles on the side, which allow you to operate the synch straps. In the above picture you see a Medium size stuff sack with a compressed MSS Patrol bag inside. As you can see, the design of the base as well as the top lid allows for very good distribution of the compression forces, which translates into extremely well packed gear. Using this same stuff sack, I can take a 0F down sleeping bag and compress it to the same size as what you see above.

Once the compression straps are loosened, and the lid is slid to the side, you can see that the bag is closed with a roll-top. This makes it completely waterproof.

In a prime example of how the little things matter, the stuff sack has a strap on the bottom by which you can pull it out of your pack. It makes a significant difference when you are trying to get you bag out without emptying your whole pack.

So, if you have been using the Event Dry Sack or other models for that matter, and have been looking for something with similar utility, but at a lower weights, the Sea to Summit Ultr-Sil Dry Sack is an excellent option. It feels significantly lighter (because it is), and folds up into a much smaller package.

At first I was concerned that the thinner walls may not handle the pressure and abrasion as well, but that doesn’t seem to be an issue. I have seen absolutely no hints of weakness, and have not felt the need to baby the stuff sack. If there are any negative developments in the future, I will let you guys know.