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

Sea to Summit Ultra-Sil Dry Daypack
Test Series by Alex Legg
Initial Report November 23rd, 2012
Field Report January 29th, 2013
Long Term Report April 2nd, 2013

Tester Information:

Name:  Alex Legg
Age:  30
Gender:  Male
Height:  6'4" (1.9 m)
Weight:  195 lb (88 kg)
Email address:  alexlegg2 AT yahoo DOT com
City, State, Country:  Tucson, Arizona, USA

I grew up backpacking in the Rockies.   I hike ranges throughout Arizona and Colorado year round.  I carry a light pack, mostly water.  I prefer a tarp shelter to my heavier 2-person tent.  I do many day hikes and I also spend as many as 5 days out at a time.  Temperatures range from below freezing to above 100 F (38 C), and elevations from 2,000 ft to 14,000 ft (610 m to 4,300 m).  I bag a mountain almost every weekend, and I walk my dogs 4 miles daily through deep sand and overgrown mesquite trees in our local washes.

Initial Report:

Product Information and Specifications:

Manufacturer: Sea to Summit
Year of Manufacture: 2012
Material: Ultra-Sil Cordura Fabric; Hypalon roll-top closure
Listed Weight: 3.2 oz (90 g)
Measured Weight: 3.6 oz (102 g)
Stuff Sack Weight: 0.25 oz (7 g)
Volume: 22 Liters (1,343 cu in)
Listed Dimensions in Stuff Sack: Not listed
Measured Dimensions in Stuff Sack: 5 in x 2.5 in (13 cm x 6 cm)
Color: Black with Grey trim

Product Description and Initial Impressions

I was shocked to see how small the Sea to Summit Ultra-Sil Dry Daypack was while packed in the stuff sack.  It is still hard to wrap my head around the idea that a pack can stuff down so tiny.  The clip on the stuff sack looks like it would make hanging the stuff sack easy.  I could see myself clipping it to a larger pack or to a hook in my car. 

As I pulled the pack out of the stuff sack I was very careful to remember how it was folded so that I could get it back into the stuff sack.  I unfolded the pack, feeling the slick, smooth surface of the Ultra-Sil Cordura fabric.  I have used Sea to Summit products made with this material before and I am impressed by their slick feel and water resistance.  Although this pack is small and lightweight, the material feels pretty strong when I pull on it.  I can see the cross-stitched pattern on the fabric when I look closely.  I assume this adds strength to the pack.

I also see many double stitched seams that the manufacture claims are fully tape sealed.  They say that the high density PU seam tape as well as the Cordura fabric make for a water resistant feature unless the pack is fully submerged.  My experience in the past with this material reminds me that water from a light rain will just bead up on the surface of the fabric.

The color of the pack I am testing is black with grey trim.  The Sea to Summit logo is printed vertically along the left portion of the front of the pack.  Across from the logo, a tag reading Cordura Brand Fabric is located.  Under this tag is another smaller tag clarifying that the pack is made in China.

The shoulder straps are smaller than any other pack I own, and made from the same material as the rest of the pack.  They are about 2 in (51 mm) wide at the top and get progressively smaller to about 1/2 in (13 mm) wide as they get toward the bottom.   They connect at the bottom to a small strip of nylon about 1/4 in (6 mm) wide.  The nylon weaves through a small plastic adjustment piece where I can adjust the straps to my desired length.  A small nylon loop is mounted in the middle of the two shoulder straps at the top of the pack.  I supposed I could hang the pack by this loop, but I am honestly surprised to see such a lightweight pack having this extra weight feature.

Along the front of the pack is the reflective compression lacing system.  It crisscrosses diagonally down the front of the pack.  I foresee this having multiple uses from storing my water containers to possibly an extra layer of clothing.  There is a small clasp at the top of the lacing system to allow me to cinch down the laces while stowing items. 

The double Hypalon strip at the opening of the compartment creates the roll-top feature of the pack.  Writing on it tells me that it must be rolled at least 4 times and buckled to make the seal.  The plastic clips are small, only about 1 in (25 mm) thick, but they feel pretty durable.  Inside the compartment there is a snap that I can connect the stuff sack to in order to create a makeshift pocket.

Trying it out:

After fully inspecting the pack, I made my first attempt at folding it tightly to pack it back into the stuff sack.  I tried to mimic the way it had originally came, but I had no luck.  I unrolled the pack and tried another time with the same result.  Then I decided to try a different method and just couldn't get it to fit.  At this point I figured the pack would never go back into its home inside the stuff sack.  After going back and forth with the pack at least ten tries, I got everything to fit in except one of the clips.  That looked good enough for me and I set it aside.  Later when I pulled the pack out again to show some friends I had similar results while attempting to repack.  This time it only took me about four or five tries and I got the entire pack to fit in nicely.  For me, it is not an easy feat to get the pack back into the stuff sack, but since I am getting better already I would imagine that I will have it down before too long. 

As excited as I was to get out and use the pack, I had to wait a day before I got the chance.  I quickly stuffed a base layer, some food and water, and a few First aid items inside and set out with my dogs.  We only trekked about 3 or 4 miles before we had to come home, but I still got a chance to get an idea of how the pack felt. 

I have my concerns about the small shoulder straps possibly becoming uncomfortable if the pack is loaded to its full capacity.  Without the assistance of a hip belt to counter some of the weight, the shoulder straps feel as though they may dig into my body a bit. 


I am very excited to get out and use this pack.  Day hikes and peak bagging are some of my favorite things.  I will take it on many day hikes and also on some backpacking trips where I will primarily use it as a summit pack.  I am impressed by the lightweight and strong feeling fabric and hope I get to see how it holds up to water.  My biggest curiosity with this pack is whether or not I can use it for an ultralight overnight pack.  It seems like it would be tight, but I will give it a go and report back for my field report.

Things I like:                              

1. Lightweight
2.  Water resistant
3.  Simple design


1.  Shoulder straps may dig into my skin
2.  Not easy for me to repack into the stuff sack

Field Report:

Field Conditions:

I have carried the day pack on many different occasions.  There have been lots of day hikes, a few backpacking trips, and a number of times when the pack was used as a makeshift shopping bag at my local supermarket. 

I have taken the pack on 5 day hikes in the Tucson Mountains.  Each trip was between 5 mi and 12 mi (8 km and 19 km) and the conditions were mostly sunny and dry.  The elevation ranged from 2,500 ft to over 4,500 ft (762 m to over 1,370 m) and temperatures ranged from 35 F to 85 F (2 C to 29 C). 

I took the pack on 3 trips to the Mt. Baldy Wilderness Area, south of Tucson, Arizona.  On each trip I covered from 9 mi to 15 mi (14 km to 24 km) in varying conditions of sunny and dry to light and down pouring rain.  Temperatures have ranged from 25 F to 65 F (-4 C to 18 C) and elevation has ranged from 4,500 ft to over 9,000 ft (1,370 m to 2,743 m).

I also took the pack on an overnight trip to serve as my summit pack in the Santa Rita mountains in southern Arizona.  The daypack was only on my back for a 6 mi (10 km) stretch, and was otherwise filled with clothes and used as a dry bag before being stuffed into my larger pack. The temperature ranged from 7 F to 40 F (-14 C to 4 C) and the conditions left me in the fog and rain the entire time.

Performance in the Field:

This pack has been fun so far.  I like how nonexistent it feels on my back.  I haven't been carrying much water since the weather cooled down, so I have had some very light loads.  Most days I don't even get close to filling up the bag.  After stuffing all the things I think I need for a trek I find that there is still a good amount of room to spare.  The roll-top closure allows the pack to be cinched down tight even when there is plenty of empty space inside.  I often load it with a base layer (1 pair pants and 1 shirt), a lightweight synthetic fill jacket (used primarily to add shape to the pack), food and water (trail mix, protein bars, 2 L water), and survival essentials (waterproof matches, fire starter, petroleum jelly soaked cotton balls and para cord all stuffed into a freezer bag and then into a warm beanie).  This pack fits all I need and more for most day trips.

I haven't had any trouble with moisture getting into the pack as long as the roll-top closure was properly closed.  The only times I had issues with outside moisture entering the pack was a day when I was forced to take a hydration bladder and stuff it into the pack because my dogs had their way with my water bottles.  As a last minute fix, it wasn't all bad.  The mouth piece tube had to stick out the main opening while I rolled the top closed around it which left an opening to the inside.  Even with the opening compromised by the tube, what got into my pack was more of condensation from the warm air melting snow all around me rather than actual water getting in.  My base layer inside got a little damp but that was it.  There was no actual water to dump out and the inside of the pack air dried on the passenger seat during the drive home. 

This pack is very good at keeping outside moisture outside where it belongs.  The issue seems to be that it has the same weather stopping abilities on the inside.  The Ultra-Sil material shows noticeable difficulty in allowing inside moisture to escape.  Moisture from food, water bottles and sweaty clothes gets stuck inside and condensation forms on the inside of the pack much like on the inside of certain tent walls.  I can't say that this has caused me any problems, but it is an observation worth mentioning.  I wonder if left out a few days during the warmer months, I could end up with an entirely unique little ecosystem thriving inside the pack.  Time will tell I suppose.

I was a little bummed when my collapsable water bottle didn't fit securely in the small compression straps on the front of the pack.  No matter how tight I cinched them they wouldn't hold the bottle in any secure way unless I used excess slack to tie the bottle up.  I didn't like fighting to get the bottle removed, so I carried my water inside the pack.  At this point I figure if my biggest complaint is not being able to stow a water bottle on the outside of the pack, then it must be a cool little pack.  So many of my other small day packs have too many compartments and zippers that don't do much more than add bulk and weight.  I tend to find all sorts of random things I have stowed and forgotten about inside the many little pockets.  Most of which are things I don't really need to have with me.  I have been able to use the compression straps for other things such as holding hiking poles and a wet shirt, so they haven't turned out to be useless at all.

I think that the conservative design of this daypack is a good approach to my style of hiking.  Having only one compartment causes me to look at everything I have inside every time I open it up.  It forces me to think about what I have brought and to keep me from giving myself a hard time, I only bring the things I need when I use this pack.  I really judge what does and doesn't need to go along with serious scrutiny.  I have found that I carry far less items using this pack than I do with my other day packs.

The lightweight material that this pack is constructed of is a lot more comfortable than I had suspected.  The shoulder straps are thick enough where they rest on my shoulders to be able to handle a lot of the weight.  They don't dig into my body like I had wondered in my Initial Report, and they are quite comfortable.  They seem to adjust easily and effectively with one hand while I'm on the trail.   

I have carried the pack on a bunch of day hikes both long and short.  It has been in rain and snow showers lasting hours at a time.  I have even left it outside while at my house test the water resistance and I am pleased to say that after an entire night of steady rain, all the contents of the bag were dry.


So far this is just the type of basic, low maintenance minimalist day pack that I was looking for.  I love how confident I am during a storm that my belongings are dry.  I also love how much I forget that I am carrying a pack at all.  I am now interested in finding a similar designed pack that also has some wicking abilities so that I don't grow a swamp inside during the warm months.  Overall I am having a blast testing this pack and I look forward to the Long Term Report phase.

Things I like:

1.  Tiny pack that holds all I need
2.  Water does not penetrate
3.  Comfortable enough to forget about

Things I don't like:

1.  No luck wicking moisture from the inside
2.  Can't carry my water bottle on the outside

Long Term Report:

Field Conditions:

I have used the day pack on many trips in southern Arizona and most recently in northern Colorado.  I have also used the pack as a convenient reusable shopping bag that can be carried in my pocket.  Some of the backpacking and hiking trips that I carried the pack on are listed below.

I took the pack on a 2-day 1-night trip to the Catalina Mountains north of Tucson, Arizona.  I loaded the pack with extra clothes before stowing it in my larger backpacking pack.  The day pack was then used for adventures away from camp.  The elevation was around 7,500 ft (2,286 m) and the temperature ranged from 25 F to 55 F (-4 C to 13 C).

I took the day pack on many trips to the Tucson Mountains west of the city.  Trips ranged from 2 mi to 12 mi (3 km to 19 km) in temperatures of 50 F to 70 F (10 C to 21 C).  The elevation ranged from 2,200 ft to 4,500 ft (671 m to 1,372 m).

I also wore the day pack on more than ten outings in Roosevelt National Forest in northern Colorado.  Distances ranged from 2 mi to 15 mi (3 km to 24 km) in temperatures of 15 F to 45 F (-9 C to 7 C).  The elevation ranged from 6,500 ft to over 12,000 ft (1,981 m to over 3,658 m).

Performance in the Field:

The Day pack has worked out great!  I am able to stuff as much food, water, and gear as I need for all day trips of 15 mi to 20 mi (3 km to 32 km).  If my ultra-light sleeping bag was compressed I could easily use the pack for an overnight trip as long as it's warm enough outside to sleep under a tarp and leave my tent behind. 

I love knowing that my gear is going to stay dry.  Many of the day hikes I have gone on in northern Colorado were in pretty snowy conditions.  Lots of the white stuff fell on the pack from the sky and the trees, but none of it ever got inside.  I felt safe tossing the pack on the snowy ground during breaks knowing that my stuff was going to be alright.

I don't carry any especially wet food such as fresh fruit or ham sandwiches in the pack due to the moisture collecting inside and dampening my clothes.  A water bottle alone can cause some moisture to form even with the cap tightly secured, but it is a manageable problem but limiting food items that are rich in water.  Lots of individually packaged granola bars and trail mixes have been the main food staples most of the time. 

The pack has remained as strong and new looking as it was when I originally opened the box.  I have impressed some other trail users by how many items I can store inside without the straps digging into my shoulders.  People have also been pretty impressed when I pull the stuff sack out of my pocket at the grocery store and bag up my food into my neat little backpack.  This is such a cool product that it has started numerous conversations from people in the backpacking community and by many outside of it.  It has been a fun thing to talk about.

I can't say that stuffing the pack back into the stuff sack has ever gotten easy, but I can get it in without too much trouble.  I find that I have to be in the right mindset to properly fold and roll the pack up because it does take some skill.  I still wish the stuff sack was a tiny bit bigger, or maybe just a bit more stretchy.  I think a more stretchy stuff sack would really ease the process of packing the day pack up.


Overall I really like this product!  It is small and sensible, yet provides ample space for all that I need to spend a day in the hills.  My rain gear, food and water, and first aid kit fit with plenty of room to spare.  I have never had a problem with outside moisture getting in, and have learned to manage the internal ecosystem from getting too humid.  The pack is comfortable and strong, and I look forward to using it a whole lot more in the future.

Things I like:

1.  Water proof
2.  Lots of space inside
3.  Packs into a super convenient size

Things I don't like:

1.  Moisture can form inside from food items and water.

I would like to thank Sea to Summit and for the chance to play with this cool day pack!

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

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