What Makes a Good Dry Bag?

Here’s a quiz for you…

Which product keeps your gear dry, sorted by type and color-coded inside (and even outside) your backpack? What holds your muddy/snowy touring ski boots and prevents them distributing slush and grit all over the back of your station wagon? What squishes down into small or odd-shaped spaces in your sea kayak or fishing sit-on-top and keeps things dry and easily accessible? What keeps your surfing or scuba gear from spreading sand or residual water over the rest of your gear? What is indispensable in a travel bag or duffel to keep wet things away from dry things or vice versa?

Time’s up; pencils down.

The product in question is the Lightweight Dry Sack. If you own one (or several…) you’ve probably put it to a number of the uses above, plus a whole lot more that we didn’t have space for. And if you don’t own one, you may be forgiven for wondering what the fuss is about. I mean, it’s just a dry sack, right? And aren’t all dry sacks pretty much the same?

They are not.

Let’s start with the fabric that the Lightweight Dry Sack is made from.

It’s a 70 Denier, 210 TPI thread-count nylon with a PVC-free polyurethane coating waterproof to 10,000mm hydrostatic head. The coating is a bright white color to allow you to easily find small items at the bottom of the bag. If you’re a fabric geek, these terms and numbers will interest you. For the majority of backpackers, paddlers, hunters or other outdoor users, the important aspects of the fabric are that it is relatively light, surprisingly tough and very squishable. If the only dry sacks you’ve encountered are stiff and bulky, this last point will amaze you. The fabric is also extremely waterproof, although there are some points on this subject that we cover in another blog post.

The fabric is then sewn together using doubled seams with a very short stitch length. The shorter and tighter the stitch length, the stronger the seam. These seams are sealed with the highest quality seam tape that money can buy.

The roll-top of the Lightweight Dry Sack is constructed using a polypropylene stiffener and a seal strip made of a synthetic rubber called hypalon (originally developed by DuPont). Hypalon does not wick moisture, nylon webbing does. Hypalon costs more than nylon webbing; Sea to Summit builds up to a quality, not down to a price.

But wait, there’s more.

The buckles on the Lightweight Dry Sack (and indeed on all Sea to Summit dry bags and dry sacks since Autumn 2017) are Sea to Summit’s patented Field Repair Buckles. These offer a few advantages over conventional buckles:

• If a buckle should become damaged, you don’t need a sharp blade to open up the seal strip and a sewing machine to reattach the strip, you need a screwdriver. It will take you two minutes to replace a Field Repair Buckle, and the repair is permanent.
• The Field Repair Buckles can be located closer to the edge of the dry sack than a conventional sewn buckle, which allows the roll-top closure to be rolled more tightly.
  
• The Lightweight Dry Sacks also have a D’Ring located next to the buckle on the seal strip which is ideal for attaching the Dry Sack to a boat, or the rack of a touring bike or motorcycle.
  

Sea to Summit has lighter-weight dry sacks for backpackers who want to create a modular packing system inside their backpack (and do not require a paddle-compatible, external use dry bag). Ultra-Sil Dry Sacks are ideal for this. And for compressible items, the eVac Dry Sacks are truly amazing – air just squeezes out through their waterproof, air-permeable base as they are pushed into a tight space. You can read about modular packing here.

Whichever Sea to Summit dry bag or dry sack you choose, you will discover over time what industry insiders and hardcore outdoor users have long known to be true: the quality, durability, and functionality are unmatched. The argument is pretty cut and dry…