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Reviews > Packs > Frameless Backpacks and Day Packs > Sea to Summit Ultra Sil Dry Day Pack > Test Report by Ray Estrella

Sea to Summit Ultra-Sil Dry Daypack
Test Series by Raymond Estrella

INITIAL REPORT - November 20, 2012
FIELD REPORT - January 26, 2013
LONG TERM REPORT - April 08, 2013


NAME: Raymond Estrella
EMAIL: rayestrellaAThotmailDOTcom
AGE: 52
LOCATION: North Western Minnesota, USA
HEIGHT: 6' 3" (1.91 m)
WEIGHT: 225 lb (102.00 kg)

I've been backpacking for over 30 years, all over California, Minnesota, and many western states. I hike year-round in all weather, and average 500+ miles (800+ km) per year. I make a point of using lightweight gear, and smaller volume packs. Doubting I can ever be truly ultralight, I try to be as light as I can yet still be comfortable. I start early and hike hard so as to enjoy the afternoons exploring/chilling. I usually take a freestanding tent and enjoy hot evening meals. If not hiking solo I am usually with my brother-in-law Dave or my twin children.


The Product

Manufacturer: Sea to SummitBoxed up
Web site:
Product: Ultra-Sil Dry Daypack
Size: one size
Year manufactured: 2012
Weight listed: 3.2 oz (90 g)
Actual weight: 3.7 oz (105 g)
Stuff sack weight: 0.25 oz (7 g)
Volume: 1343 cu in (22 L)
Torso length: N/A
Color: Black

Product Description

The Sea to Summit Ultra-Sil Dry Daypack (hereafter referred to as the pack or daypack) is a top-loading frameless daypack. Trying to find it on the company web site is a bit difficult as they have it grouped with Storage Sacks. I suppose that makes sense as it is a dry bag with shoulder straps attached. ;-)

Front, back, side

The body of the pack is made of Ultra-Sil, a siliconized Cordura fabric. I have three of the company's smaller Ultra-Sil dry bags so am quite familiar with the material. Being made in the shape of a pack it has more seams than I am used to seeing on a plain dry bag so Sea to Summit double stitched them all for strength and applied seam tape to them to insure that water stays out.

The top has a standard roll-top closure, with the edge being strengthened with Hypalon, a type of synthetic rubber. Once the top is rolled down to seal off the pack the ends are attached by way of a Dura-flex quick-connect buckle.

Zigzagging across the face of the pack is a narrow gauge reflective cord that goes through a cord-lock and six nylon loops, three on each side. This is the only added storage feature, there are no pockets, tool loops or daisy chains.

On the other side of the pack are the shoulder straps which are connected to the body with a rudimentary reinforced yoke. They have narrow nylon webbing adjustment straps at the lower end of the shoulder straps that pulls the pack higher onto my shoulders and back. There is no waist belt or sternum strap. A small hang loop is connected to the yoke centered between the shoulder straps.

The Dry Daypack came packed into a tiny stuff sack that, as soon as I unpacked it, I realized I would never get it back into. It is tight! The stuff sack has a little tab of Hypalon with a snap that they say is a key fob.

Looking inside the body of the daypack there is nothing except a little snap at the end of a short reinforced tab, just the male end. For the life of me I could not figure what it was suppose to hook to. Then it hit me that the key fob has the same snap. I attached the stuff sack to the inner snap and voila! There is now a place to keep small things from being lost in the bottom of the pack. Here is a picture of the stuff sack attached inside the pack.

Stuffed and hanging like a chad...

While the Ultra-Sil Dry Daypack is positioned as a daypack I am also going to use it as a dry storage for my winter down items, quilt, sleeping bag, down hood, parka, etc. while riding in my backpack or gear sled. Then once in camp I shall use it as a daypack.

That's all I can find to say about it, so let's call this report finished. Please come back in a couple of months to see how the Ultra-Sil Dry Daypack works for me in the field.


Field Conditions

Sitting in tent

So far I have taken the Ultra-Sil Dry Daypack on seven overnight trips this fall and winter. Five have been on private land north of Halstad Minnesota (MN), one on public land north of Moorhead, MN, and one on public land north of Hendrum, MN. In the picture above the Daypack is laying next to my pad & quilt.

Temperatures have been from about 40 F for a high in November to lows of -15 F the other two months (4 to -26 C). There has been rain on a couple of trips and light snow on a couple others.


The Ultra-Sil Dry Daypack has been a fairly useful little item for me this winter. Its main use has been as a stuff sack for my quilts and sleeping bags, sometimes even both at once! With smaller items like a 30 F (-1C) rated quilt I will stuff the quilt in the Daypack and then leave the top open when I place it in the bottom of my backpack. This lets the weight of my other gear compress it. But with bigger items like my 0 F (-18 C) rated bag combined with a over-quilt I compress it first and roll the top down, attaching it to keep the size in my pack manageable. Both ways have worked very well. In this shot I am waiting to pull a 5 F (-15 C) quilt out once my pad finishes inflating. Yeah I am lazy…

As a stuff sack with bag

I have even used the Daypack as a stuff sack for a tent a couple times. The Brooks Range Propel in the picture above has a very tiny stuff sack and it is very hard to get back in at the best of times, even harder once there is any moisture on the tent. Add to that the fun of dealing with anything wearing thick gloves when it is very cold and it becomes a truly frustrating project. So I put my sleeping bag directly into the bottom of my pack, then my other gear on top of it. Then lastly, to keep everything from getting wet, I stuffed the Propel into the Ultra-Sil Daypack placing it on the top of my load. Once home I remove the tent in the garage and shake out all the ice and water, turning the Daypack inside out to let it dry in the house. Here is a shot stuffing that tent on a -15 F (-26 C) morning.

As a stuff sack with wet tent

It works OK as a daypack. During the fall I was wishing it had some way to use an insulated hydration bladder with it, but once winter hit it is too cold for even them. But an outside pocket would be really nice to keep from having to undo the top when I want to get a drink or pull out a trail bar. I don't carry much in it as my dayhiking has all been from my established campsite and I don't go much more than a mile (1.6 km) or so from it as I explore new sections of woods or the river bluffs. Water is the heaviest part, then lunch, extra gloves, and a fleece or light puffy jacket and PLB. Here is a shot using the Daypack along the Red River.

And as a daypack

If we ever get enough snow to use snowshoes I will use it for true dayhiking, maybe during the Long Term Report phase. Which starts right… now! That means this report is done, so come back in a couple months to see if we ever got snow and how the Ultra-Sil Daypack worked out for the big finale.


Field Conditions

During this phase of testing I used the Ultra-Sil on three backpacking trips. One was on the North Country Trail by the Anoway River in Chippewa National Forest, one on the North Country Trail in Paul Bunyan State Forest, and the last in Smoky Hills State Forest where I camped near the Shell River. These trips were cold with lows averaging around -5 F (-21 C). The trip on the Anoway River saw -22 F (-30 C). All campsites were on snow.


As the test progressed we saw one of the coldest ends of winter/beginning of spring in a long time in my neck of the woods. I used the Ultra-Sil as a dry bag for my sleeping gear for all the trips, and once more used it to carry my wet frozen single-wall tent on one of the hikes back to the trailhead.

This time I did not use it as a stand-alone daypack as it really does not function well as one with its lack of pockets or hydration ports. But it was my only pack while on two of my backpacking trips since I used a gear sled for them.

I think that the beauty of the Ultra-Sil is that it does its main job of keeping gear dry very well. The usefulness as a day pack is just an added bonus that does not cost much in terms of weight. And that is how I will use it in the future. For most straight day-hikes my dedicated day-pack works better for the job.

That's about all I can find to say about this ultralight multi-function piece of gear. My thanks to Sea to Summit and for allowing me to put it to the test.

This report was created with the Report Writer Version 1.5 Copyright 2013. All rights reserved.

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