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Reviews > Stuff Sacks > Dry Bags > SealLine Blockerlite Dry Bag > Test Report by Coy Ray Starnes

SealLine BlockerLite dry sack
Test Report by Coy Starnes
Initial Report: July 21, 2017
Field Report: October 4, 2017
Long Term Report: December 5, 2017

Coy Starnes
245 lb (111 kg)
6 ft (1.8 m)
Grant Alabama

Tester Biography
I live in Northeast Alabama.  I enjoy biking, hunting, fishing, canoeing/kayaking and most other outdoor activities, but backpacking is my favorite pastime.  I enjoy hiking with friends and family or solo.  I hike throughout the year and actually hike less in the hot humid months of summer.  My style is slow and steady and my gear is light.  However, I will sacrifice weight for comfort and durability.  A typical 3-season load for me is around 20 lb (9 kg) not counting food or water.
Initial Report: July 21, 2017

Product Information
Test Item: SealLine BlockerLite dry sacks
Manufacturer: Cascade Designs
Manufacturer Website:
Year of Manufacture: 2017
Size: 2.5 L (153 cu in), 5 L (305 cu in) 10 L 610 cu in), 15 L (915 cu in), 20 L (1220 cu in)
Weight: varies (see photo below)
Colors Available: Blue, Yellow, Orange, and Coral
MSRP: 2.5 L $15.95, 5 L $18.95, 10 L $21.95, 15 L $23.95, 20 L $26.95

SealLine BlockerLite dry sack
                my post office weights match the above save one small detail explained later in report

Product Description and Initial Impressions
Who knew writing a dry sack Report could be so involved....I mean, it's just a waterproof stuff sack, or in this case, five dry sacks.  For starters, I haven't used "backpacking " dry sacks before.  I have used regular stuff sacks and I've used backpacking designed ponchos, pack covers along with trash bags and zip-lock bags inside my pack for gear I really needed to keep dry.  Anyways, here is my take on the SealLine  BlockerLite dry sacks.

SealLine falls under the umbrella company Cascade Designs.  SealLine makes a variety of dry sacks but the BlockerLite is the lightest.  These come in five sizes and four choices of color for each size.  This means there will be a color overlap if all five sizes are purchased.  In my case it happens to be the smallest two sizes, the 2.5 L and the 5 L which are coral (red).  I also got an orange 10L, a yellow 15 L and a blue 20 L.

These stuff sacks are made of 20D silicon polyurethane-coated nylon.  I am familiar with this material since I have a hammock fly made of the same lightweight material.  Interestingly, the regular Blocker stuff sacks are made of 70D material and are almost 50% heavier, much like my 70D hammock fly.  As an example, the 20 L BlockerLite weighs 2.1 oz (60 g) while the regular 20 L Blocker weighs 3 oz (85 g).

They are constructed with welded seams which means no stitching.  According to the website this is actually 50% stronger than sewn seams.  The bottom of each stuff sack is rectangular in shape as opposed to round.   This is supposed to make them pack more efficiently, 20% more according to the packaging.   They utilize a roll top closure.  I'm not sure what is inside the sleeve that makes up the stiff part but it keeps the top part straight so that it can be rolled evenly with no way for air to enter.  Speaking of sealing, the directions that came with each stuff sack specifically state these are not designed for immersion, rather they are designed to protect items from rain, splash and spray and are not intended for submerged use.

When I first got the dry sacks I removed them from the packaging but left the little rubber bands on so I could go weigh them at the post office.  At the time I didn't realize the instructions were folded up with each one so I actually weighed the dry sacks and the instructions.   As a result, my weights were consistently 0.1 oz (about 3 g) heavier than the listed weighs.  But that's neither here nor there.  These suckers are light.  About the only way to get any lighter would be to go with Cuban fiber which cost substantially more. I also could not get the ones I unrolled and opened to close back as neatly as they were. Oh well, I think this is pretty normal.

SealLine BlockerLite dry sack
                                                      my re-folding of empty dry sack vs factory

Trying them out
I haven't had a chance to put these to use but I did take the time to see if my 10 F (-12 C) down under quilt would fit in the 15 L dry sack. It was no problem to stuff it but because the material is waterproof it felt different than stuffing it in the non-waterproof stuff sack it came with. Basically, I had to expel the air through the under quilt when normally it passes through a little of both. I had room left over and rolled the top down four times before snapping it shut.  I was curious to see if I needed to end upon an odd number of rolls since the directions say to roll it three times but apparently this is no big deal.  I think three roll is the minimum because two just did not feel very secure (I tried it to see).  I could probably squeeze the under quilt in the 10L but I prefer not to squish my down gear any more than necessary and it would also stress the smaller sack more.  I'll experiment with the different sizes and what I pack in each as the test progresses.

SealLine BlockerLite dry sack
                                                  15 L size with my 10 F (-12 C) down under quilt

Field Report: October 4, 2017

Test Locations and Conditions
I have used the SealLine BlockerLite dry sacks on two overnight trips so far.  Both trips were in local woods near my home.  Fortunately, I have some very nice hiking areas right out my front door.  My first trip was August 3rd and I hiked 6 miles (10 km) total.  The high temperature was 88 F (31 C) and it did sprinkle about 15 minutes during my hike to my campsite.  It slowly cooled on down to 69 F (21 C) during the night.  My last overnight hike was a short 4 miles (6 km) total on August 22nd.  It was 84 F (20C) when I headed out but only dropped down to 71 (22 C) for the overnight low.  No rain was experienced on this trip and the air felt more fall like even though the temperature was still rather warm.

Field Test Results
I used the dry sack in the same manner on both overnight trips.  Since it only sprinkled once during my time afield with the dry sacks I cannot really report on how well they worked at keeping my gear dry other than to say, my gear stayed dry.  However, they did make organizing my gear a little easier.  Before getting these dry sacks I had been putting the long skinny stuff sack that holds my REI Quarter Dome Air hammock on one side of my backpack and cramming my under quilt and top quilt in on the other side, with some spilling over and above the hammock stuff sack.  This left plenty of room at the very top of my pack to cram in food and other essentials.  As can be seen in the photo below, once I placed my synthetic under quilt in the 15 L yellow dry sack beside my hammock there was no way to get the synthetic top quilt in the 10 L orange dry sack in the lower section of my pack.  I ended up putting it on top and it took some cramming to get it in.  This meant I had to cram my food in whatever leftover spaces I could find.  I was still able to fit all the gear I normally kept inside the pack, it was just not as easy as before.

SealLine BlockerLite dry sack
   Sleep gear in the 15 L yellow and 10 L orange SealLine BlockerLite dry sacks

I placed my wallet, some toilet paper and a few other odds and ends inside the smallest 2.5 L dry sack which was then squeezed into the top lid of my backpack.  Due to the skinny nature of the top lid opening and overall small volume of this area on this pack I had to let the air out completely before putting it inside.  It was still a struggle to get it in but didn't appear to damage the dry sack.

SealLine BlockerLite dry sack
                          SealLine BlockerLite 2.5 L dry sack in top lid

Once at camp I did like that I could keep my top quilt and bottom quilt neatly stored as I went about setting up my hammock.  Normally they might be hanging partially out of my pack and then haphazardly placed over or inside my hammock before really needing them for warmth.  These dry sacks are not compression stuff sacks which might help make more room inside my pack but I felt I was stuffing my sleep gear down as small as wanted too.  If critical I could have sat on them while unsealed and perhaps got another wrap on the roll top closure.  However, I'd rather just use a roomier pack.  So, in coming months I will to be using a larger pack suited for winter gear.  Right now I plan to carry my spare clothes in the 5 L.  However if I need more room for clothes I might use the 10 L, then use the larger 15 and 20 L dry sacks for my sleeping gear.  That's all for now.

Long Term Report: December 5, 2017

SealLine BlockerLite dry sack
                            The 20 L (blue) and 15 L (orange) stuff sack reporting for duty.

Test Locations and Conditions
My last two overnight hikes were on local trails near my home in Grant, Alabama.  The first one was on October 18th, I hiked about 4 miles (6 km) total, the overnight low was 50 F (10 C).  My second overnighter was on December 4th.  I hiked approximately 6 miles (10 m) total and the overnight low was 54 F (12 C) but it was one of those strange nights when it actually warmed up a little during the night.  It also rained off on and on during the night.  On both hikes I crossed creeks and small streams and went up and down several steep hills.

Long Term Report
I have continued to use the SealLine BlockerLite stuff sacks in much the same manner as before but the least two trips were with a larger backpack.  This gave me room to use the larger 20 L stuff sack without taking up all the room for other gear so on my last trip I basically swapped from the 15 L to it and used the extra room to pack a light down jacket along with the synthetic top quilt I had squeezed into the 15 L stuff sack previously.  Both fit with room left over so I just rolled the roll-top closure down a few more rounds.

On the October 18th hike it was 64 F (18 C) when I left the house.  I hiked 3 miles (5 km) before stopping for the night.  By then it had dropped down to 57 F (14 C) and was cooling down fast.  I got my hammock setup just before dark and settled down to relax awhile. I started off with my t-shirt under a shirt jacket and sweatpants.  I also had on some fairly thick cotton socks.  I had worked a 24 hour shift the previous day so by 8 PM I was getting sleepy.  I decided to try the 10 L as a pillow by filling it about half full of air.  Unfortunately, it slowly deflated in about 20 minutes.  No biggie since I had the shirt jacket handy and just used it the rest of the night.  I had the orange stuff sack with me but it held my top quilt.  I was testing a survival bivy sack so had not even pulled it out of my backpack.

On the December 4th hike it was 61 F (16 C) when I headed out.  I hiked 5 miles (8 km) before stopping for the night.  It was only 4 PM but starting to get dark already.  I knew this would mean for a long night but the long hike had worn me out so after a few snacks and relaxing in the hammock I found myself really sleepy.  I decided to try a stuff sack as a pillow one more time but this time I used the much longer 20 L and left the down jacket it was now carrying inside.  I also rolled it down a few extra rounds for good measure.  Low and behold, it held air.   However the slick nylon did not feel all that great so I put my shirt jacket over it.  This actually made a pillow on par with one I would use at home.

SealLine BlockerLite dry sack
Successfully using the 20 L (blue) stuff sack as a pillow.

Anyways, after about an hour nap I woke up and stayed awake a few more hours before going back to sleep for the rest of the night.  Well, I didn’t sleep the whole time, it was really windy and then started raining around 1 AM so I was awakened several times by various noises during the night.  At around 3 AM it started raining hard and the stuff sack was still holding air but was slightly less inflated than it was several hours earlier.  I decided that since I had not had an opportunity to really see how waterproof the dry sacks were this would be a good time to find out. I gently tossed it outside my hammock well away from the rain fly and went back to sleep with just the shirt jacket as my pillow.  I woke up for good right around daybreak. It had just stopped raining but my phone was showing more on the way so I hurriedly packed my gear without using the stuff sacks other than the down jacket already inside the blue one.  I got home and hung my wet fly on the deck to dry, then turned my attention to the 20 L (blue) stuff sack.  It was very damp on the outside.  I pulled the jacket out, careful not to let it touch the outside of the stuff sack and inspected it closely.  It appeared to be completely dry.  I felt inside the stuff sack and it felt cold but was dry as well. While not a scientific test, I was pleased with the performance of the dry sack.

SealLine BlockerLite dry sack
                                                                                  wet dry sack....

Final Thoughts

Using the SealLine BlockerLite stuff sacks made it easier to organize my gear but the real bonus was the peace of mind they gave me knowing my sleeping gear and spare clothing would stay dry.  The fact they they are also very lightweight made the choice to use them a no-brainer.  Using them as a pillow gave mixed results but I believe my first attempt would have worked if I had rolled the roll-top closure down a few more rounds.  Either that or the blue one is more air proof then the yellow one.  Regardless, it is good to have an item that serves several purposes.

This concludes my testing of the SealLine BlockerLite stuff sacks.  I would like to thank and SealLine for this testing opportunity.  Stay tuned for my Long Term Report in approximately two months for an update.

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