A Bag So Good, You may Put on It Awake: Sea to Summit Ascent Sleeping Bag Evaluate

I may inform it was getting colder within the tent — and quick. I’d stored up with the wooden furnace for a couple of hours, however I bought bored with getting up each half-hour to load new logs and stoke flames out of it. In addition to, I used to be right here to check my sleeping bag, and I wasn’t going to actually do this if I stored it too heat.

So, I ended getting up and the fireplace died. The temperature began dropping. I knew it was going to get near zero tonight. I may hear snow falling in opposition to the nylon partitions. Finally, I may see my breath. However I used to be so comfy and heat, I dozed off inside minutes, wrapped within the Sea to Summit Ascent.

Within the morning once I awakened, the partitions have been lined in frost. My water bottle had frozen. And I didn’t need to get out of my bag to face the frigid day. Fortunately, I remembered I didn’t should. I reached down and unzipped the foot field of the bag, caught my ft out and into my Sorel boots, and bought as much as make espresso. That whole morning, I wore my sleeping bag round camp.

I used to be actually beginning to like this Sea to Summit Ascent.

Briefly: The Sea to Summit Ascent sleeping bag is without doubt one of the most versatile sleeping baggage I’ve ever used. It’s jammed with options like a zippable foot field, vertical and horizontal baffles, outsized zipper collars, and extra. Most significantly, although, this factor places out warmth. Or, at the very least, its down baffle system traps warmth so effectively, I often discovered myself opening the a number of zipper vents to dry my sweat and funky off — even when winter tenting.

Sea to Summit Ascent Sleeping Bag

  • Weight
    2 lbs., 14.7 oz. (with common Ascent III – 0-degree)
  • Compressed quantity
    8.2 L (with common Ascent III – 0-degree)
  • Fill weight
    26.5 oz.
  • Temp. scores supplied
    25-, 15-, 0-degree
  • Sizes
    Common, lengthy

  • Extraordinarily heat

  • Dynamic free-flow zipper system

  • Made with water resistant Extremely-Dry down

  • Zips along with different Sea to Summit Ascent baggage

  • The cellphone pocket doesn’t match all sizes of telephones

  • The hood is vast and comes off considerably simply

Sea to Summit Ascent III (Zero-Diploma) Evaluate

The Sea to Summit Ascent I used was the Ascent III — the model’s zero-degree model of this bag. I primarily bought it for chilly climate adventuring: backcountry ski tenting, ski space parking zone automobile tenting, hut journeys, and so on. I figured with 750 Extremely-Dry Down fill, the Ascent would serve me effectively by means of late fall, winter, and early spring.

And boy, was I proper. The Sea to Summit Ascent bag is a heat sleeping bag. In tents, when the temp was plummeting into the one digits and right down to zero (plus or minus a couple of levels), I solely awakened from getting chilly a few instances. And each time, that was as a result of I hadn’t zipped the bag up all the way in which or I’d left the foot field unzipped, for worry of overheating.

Sea to Summit additionally treats the Extremely-Dry Down with a nano-level water-repellent polymer. The model claims that Extremely-Dry Down retains 60% extra loft, absorbs 30% much less moisture, and drys out 60% sooner than baggage utilizing common down fill.

I didn’t get my bag too moist throughout testing. However I can attest that when frost and condensation bought on it, and even soaked into it, the down didn’t clump up or get matted. And what little moisture it did take in appeared to dry out rapidly.

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
(Photograph/Will Brendza)


Not all baggage match the identical. I as soon as had a sleeping bag with loads of area within the shoulders, however that had such a tapered form that it left nearly no room for my ft to maneuver round. It was usable, although considerably claustrophobic. I’ve had different baggage which might be so spacious and loosely match, they bunch up like a blanket and clump weirdly whenever you transfer round.

Not so with the Sea to Summit Ascent sleeping bag. The relaxed mummy form gave me sufficient room to sleep naturally in any place. And on the identical time, I wasn’t swimming in it.

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
(Photograph/Will Brendza)

Noteworthy Options


The zipper system on this bag is certainly one of its coolest design options. The primary zipper on the left extends from the hood to the toes. Under that, on the very backside of the bag, a foot field zipper permits you to open the underside up. Stick your ft out and stroll round, or use it and the total aspect zipper to open the bag up right into a full-on down quilt.

A 3rd half-zipper on the precise aspect permits you to unzip the highest half of the bag (along side the full-size zipper on the opposite aspect). That makes it straightforward to sit down up or to ventilate your prime half with out exposing your backside half. All of this makes for a really dynamic zipper and air flow system.

The zippers are all additionally protected with an oversize draft tube and draft collar, which prevents heat air from escaping from them. Plenty of instances, oversize zipper cuffs like these can catch and make zipping or unzipping a tough course of. However up to now, I haven’t skilled that with this bag.

The complete-length aspect zipper can also be suitable with different Sea to Summit Ascent sleeping baggage. That means you and your companion can zip collectively, cozy up, and snuggle by means of the night time.

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
(Photograph/Will Brendza)


This sleeping bag is offered as a backpacking sleeping bag. For winter backpacking journeys, I believe the Ascent III (zero-degree) could be nice. The Ascent I and II (15-degree and 25-degree, respectively) could be nice for spring, summer time, and early fall backpacking. It’s a little cumbersome in its stuff sack and would take up a good quantity of area. However the stuff sack comes with hooked up cinch straps to actually compress it down.

At 2 kilos, 14 ounces, the Ascent isn’t an ultralight bag by any means. However that wouldn’t cease me from taking it on the backpacking path. It’s a really dependable bag.

And it’s nice for automobile tenting as effectively. There actually isn’t an outside scenario the place this bag wouldn’t be an excellent match.

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
(Photograph/Will Brendza)

Horizontal and Vertical Baffles

Most sleeping baggage solely make the most of horizontal baffles. However Sea to Summit bought artistic with the design of the Ascent and determined to make use of each. The decrease half of the bag makes use of horizontal baffles, and the higher half is vertical.

Sea to Summit says that helps to forestall down from shifting round with shoulder motion. Which, in flip, maximizes heat.

I can see how that might work — although I had no possible way of testing whether or not it did or not. For the document: I didn’t expertise the down within the torso/shoulders shifting round. And I did keep maximally heat.

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
Sea to Summit Ascent sleeping bag; (picture/Will Brendza)

Sea to Summit included an inner cellphone pocket on the Ascent. It’s a small zippered pouch on the within of the bag, so you may maintain your cellphone heat when you sleep so the chilly doesn’t kill its battery. That’s useful.

Nonetheless, my cellphone — an iPhone 11 Max — wouldn’t match. (I had to make use of my girlfriend’s cellphone to take the above picture.)

The technical hood can also be designed to entice physique warmth within the bag. A draft collar creates a barrier round your neck that stops heat air from getting out and chilly air from getting in. Nonetheless, the hood was just a little on the vast aspect. I did have some points with it coming off my head through the night time. However you too can cinch it down with a draw twine to keep away from that.

Sea to Summit Ascent Sleeping Bag: The Ultimate Phrase

Sea to Summit Ascent sleeping bag; (photo/Will Brendza)
(Photograph/Will Brendza)

Attempt as I’d, I couldn’t discover lots of locations the place this bag fell brief. The down is water resistant, it’s extremely heat, the zipper system is extraordinarily dynamic and permits for a number of totally different avenues of air flow, the zipper draft tubes and collars are all however impenetrable, and cleverly positioned vertical and horizontal baffles maintain you heat by means of the night time.

The most important pitfall of this bag is that it will get too heat in sure conditions — and it actually might be between the months of Could and September (however bear in mind, I bought the zero-degree model). And even when it does, I can open the Ascent up a number of alternative ways to chill myself off.

I like this bag. I’ll proceed utilizing this bag. And I’m going to be bummed when I’ve to place it away for the hotter months. A part of me needs I’d gotten a 15-degree model — as a result of I’d be glad to make use of this factor all yr spherical.