Sea to Summit Spark Sleeping Bag Evaluation [2025]

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This can be a gear assessment concerning the Sea to Summit Spark Sleeping Luggage in 2025. The sleeping bag assessment covers the entire Sea to Summit Spark Sleeping Bag Vary however I’ve centered on the Sea to Summit Spark 18F which I’ve extensively used and examined.

The Sea to Summit Spark Sleeping Luggage all use high-quality 850+ Extremely-Dry down, ultralight 10D outer shell cloth coated with a DWR and 10D internal cloth, they usually pack all the way down to a really small pack dimension. There are such a lot of positives to notice concerning the Spark sleeping luggage making them one of many finest light-weight sleeping luggage for 2025.

There have been a few upgrades to this bag in 2019, 2022, and 2024 which have improved points with the bag. These enhancements have additionally made the Spark sleeping luggage even higher.

Hold studying to seek out out extra.

How We Examined

The Sea to Summit Spark Sleeping Luggage on this assessment have been extensively evaluated and researched by the skilled creator who has greater than 30 years of expertise in Through-Mountaineering, Backpacking, and Mountaineering. He additionally spent a number of years managing a mountain climbing retail retailer and is considered an skilled on this subject. It was provided by the producer. They’ve been rigorously examined by the creator in every kind of climate on a number of backpacking journeys. The analysis, testing, and expertise of the creator have mixed to current this trustworthy and unbiased assessment. Learn the Evaluation Coverage for additional particulars.

Sea to Summit Spark Ultralight Sleeping Bag Specs 2025

Sea to Summit Spark 45F Specs

Weight: 12.8 oz / 363 grams
Down Fill: 5.3 oz / 150 grams
Sleeping Bag Cloth Weight (with out down): 7.5 oz / 213 grams
Down fill energy: 850+
Extremely-Dry Down: Sure
Complete down loft in cubic inches: 4,505 cubic inches of down loft
Zip: Sure, 1/2 size YKK zips
Draft Tube on Zip: Sure
Hood: Sure
Stuff Sack: Sure, a compression stuff sack
Stuff Sack: XXXS
Stuff Sack Compressed Quantity: 2.4L

Sea to Summit Spark 30F Specs

Weight: 1lb 1.4 oz / 493 grams
Down Fill: 9.3 oz / 265 grams
Sleeping Bag Cloth Weight (with out down): 8.1 oz / 228 grams
Down fill energy: 850+
Extremely-DryDown: Sure
Complete down loft in cubic inches: 7,905 cubic inches of down loft
Zip: Sure, 1/2 size YKK zips
Draft Tube on Zip: Sure
Hood: Sure
Stuff Sack: Sure, a compression stuff sack
Stuff Sack dimension: XXS
Stuff Sack Compressed Quantity: 4.3L

Sea to Summit Spark 15F Specification

Weight: 1lb 11.7 oz / 730 grams
Down Fill: 15.2 oz / 480 grams
Sleeping Bag Cloth Weight (with out down): 12.5 oz / 250 grams
Down fill energy: 850+
Extremely-DryDown: Sure
Complete down loft in cubic inches: 12,920 cubic inches of down loft
Zip: Sure, full size YKK zips
Draft Tube on Zip: Sure
Hood: Sure
Stuff Sack: Sure, a compression stuff sack
Stuff Sack dimension: XS
Stuff Sack Compressed Quantity: 6.8L

Sea to Summit Spark 0F Specification

Weight: 2lb 7.3 oz / 1113 grams
Down Fill: 29.6 oz / 840 grams
Sleeping Bag Cloth Weight (with out down): 9.7 oz / 273 grams
Down fill energy: 850+
Extremely-DryDown: Sure
Complete down loft in cubic inches: 25,160 cubic inches of down loft
Zip: Sure, full-length YKK zips
Draft Tube on Zip: Sure
Hood: Sure
Stuff Sack: Sure, a compression stuff sack
Stuff Sack dimension: S
Stuff Sack Compressed Quantity: 9.9L

STS Spark Ultralight Sleeping Luggage

When Sea to Summit first launched the ultralight Spark Sleeping Bag vary it turned successful as they chased the ultralight sleeping bag market. As soon as upon a time, ultralight backpackers and thru-hikers had been seen as freaks who compromised sturdiness and security whereas chasing decrease ounces and grams. Now ultralight is mainstream and accessible to all.

Latest upgrades modifications to among the zips on the luggage, vertical baffles to stop down shift whereas tossing and turning at night time, and an improved PFC-free DWR end. All of those enhancements have elevated the power of the bag to maintain you heat at night time, elevated the performance of the luggage, and lowered the environmental impression of the bag. Probably the greatest upgrades with the newest mannequin is the Quiltlock System which permits a Sea to Summit Quilt to connect to the sleeping bag. This might can help you connect them collectively and lengthen your sleeping bag vary into a lot colder temperatures and in some circumstances you might not want a separate Winter Sleeping Bag.

They’ve retained the beneficiant inner sizing and dedication to having the temperatures of the luggage independently examined to EN requirements.

Observe: In March 2022 a brand new sleeping bag customary, ISO 23537, was launched as the brand new sleeping bag requirements. Sea to Summit has knowledgeable me that they are going to be testing all their luggage to this customary very quickly. I like this dedication to making sure the sleeping bag rankings are independently examined quite than a finest guess on how heat you need to be like some corporations do.

Down kind / fill energy

The Sea to Summit Spark is full of 850+ Extremely-DryGoose Down in 2025. That is the high quality down used on any Sea to Summit Sleeping Bag. It’s not solely light-weight but it surely additionally has good water resistance qualities because it makes use of the water repellent Extremely-Drydown.

While you buy a Sea to Summit Bag you’re going to get a certificates from the Worldwide Down Feather Laboratory (IDFL). This certificates will state precisely what Responsibly Sourced Down was utilized in your Sea to Summit Ember sleeping bag.

After I opened my new sleeping bag I used to be stunned to study that my down sleeping bag had a barely larger fill Extremely-Drydown. The said 850+ down is the minimal customary that Sea to Summit has dedicated to placing in your Spark Bag. Generally that batch could also be a little bit larger however by no means decrease. Only a small however spectacular characteristic from Sea to Summit

Building

Let’s check out how the sleeping bag is made with options such because the Internal and Outer Shell materials, zippers, baffles, draft tubes, hood, and climate resistance.

Outer Shell cloth

The exterior face cloth of the Sea to Summit Spark sleeping bag is made utilizing a ten Denier Ripstop Nylon which is coated with a brand new PFC-free DWR coating to stop drops of water from getting into the bag. The material is so mild and so skinny it’s nearly see-through, particularly if you maintain it as much as the sunshine.

When testing the spark sleeping bag I dropped a major quantity of water on the outer cloth to check the water resistance of the material and the water beaded properly and ran off the material. I’m a fan of this ultralight outer cloth and the brand new DWR coating.

Additionally good to know if water did someway enter and get into the down the vast majority of it won’t be absorbed because of the usage of the high-quality Extremely-Drydown.

Internal cloth

The Sea to Summit Spark sleeping bag makes use of a light-weight 10D internal cloth. The ten Denier cloth will not be solely ultralight but in addition resistant to ripping.

I did attempt to rip the material with my fingers, Arnold Schwarzenegger fashion, and it was robust sufficient to not rip. Or possibly I’m simply not very robust!

Climate resistance

As talked about above, I did drop water on the outer face cloth to check the water resistance and high quality of the DWR coating. I can affirm it should present a good stage of water resistance that’s at the very least equal to or higher than all of the competitors within the Ultralight Sleeping Bag market.

The Sea to Summit Spark is nice sufficient to sleep outdoors beneath the celebs when condensation comes down in a single day.

Disclaimer: I don’t suggest that you just pour an entire bottle of water over your sleeping bag to check its water resistance.

Baffles

A few years in the past the Spark vary modified to vertical baffles within the torso space to stop down shift whereas sleeping at night time, particularly good in case you are a slide sleeper. The decrease area and backside aspect of the bag use a sewn-through design to maintain weight to a minimal.

The hotter Spark 45F and Spark 30F use full field baffles to fill extra down into the bag for better heat. Whether or not you need weight-saving or heat, the baffle design has you lined.

My solely critique was the quantity of down in every baffle might have been a little bit larger to stop down clumping. After some time the down will begin to clump a little bit, this occurs to each sleeping bag. Slight overfill will scale back the clumping impact. Washing the bag will repair the clumping points on a closely used sleeping bag.

Zips and Draft Tube

The Spark collection options both a full zip or 1/2 size zip. The 45F and 30F characteristic 1/2 size top-of-the-range YKK #3 zips and a draft tube to maintain within the heat. The 15F and 0F characteristic full-length YKK zips with a zipper draft tube.

I attempted my finest to destroy the zip and tried to snag it on the inner draft collar. All makes an attempt failed. The zip and draft collar are well-positioned and forestall snagging. This is a matter on many sleeping luggage however not the Spark sleeping bag.

The zip can snag when making an attempt to open the bag. It should snag for most individuals after they attempt to open the bag. There’s a quirk with nearly all YKK zips on sleeping luggage. In the event you attempt to open them at an angle they may stick. As soon as you realize this, and alter the way you open the sleeping bag, you’ll discover it really works nice.

Total, the zips and draft tubes do an excellent job and there may be not a lot that may be faulted.

Hood

The hood on the Spark is nice and includes a full collar the entire approach round. There may be an outsized drawcord toggle on the right-hand aspect which is a little bit greater than it must be. The toggle may be cinched tight to shut off many of the hood and depart solely the nostril and mouth in place to get contemporary air on these very chilly nights.

The neck and hood collars may very well be a little bit greater and will have extra overfilled for higher warmth retention. In my expertise the hood collar and neck collar areas of sleeping luggage are the primary locations to get soiled from physique oils and sweat which ends up in the down turning into extra compressed and clumped, making them much less environment friendly at retaining you heat.

After I examined the Sea to Summit Spark I spent lots of time sleeping on my aspect and rolling over so much. The hood did an excellent job retaining within the heat.

As talked about above, possibly a bit extra overfill within the hood and draft collars can be an excellent enchancment.

Stuff Sack

The usual Stuff Sack provided with the Spark sleeping bag is nice and there’s no want for anybody to think about upgrading to anything. It’s light-weight and may be compressed with the aspect straps to compress the luggage into a really small dimension. The Spark is without doubt one of the most compressible sleeping luggage in its class of ultralight sleeping luggage.

Compression

As talked about above the stuff sac will compress the bag to a smaller dimension. Confer with the Specification chart for detailed comparisons.

Packability

The Sea to Summit Spark collection is probably probably the most packable of all of the sleeping luggage within the ultralight class.

Consolation

The inner sizing of the Spark sleeping luggage has elevated lately. Though they’re a basic mummy fashion of the sleeping bag, they’ve been upgraded to expedition sizing which permits most customers to have the ability to put on a down jacket, down pants, or down booties contained in the sleeping bag with ease.

When testing the bag I wore my expedition-weight down jacket contained in the bag and I nonetheless had loads of room to toss and switch with out feeling constricted. When sleeping on my again or aspect I discovered it to be snug and in a position to preserve me heat with no points to report.

An affordable method to flip your bag right into a winter sleeping bag is to make use of one other sleeping bag or quilt with any of those luggage. The beneficiant sizing will can help you use one sleeping bag inside one other, thus turning your 3-season sleeping bag right into a 4-season winter sleeping bag at a less expensive worth.

Heat

When testing the bag I discovered the temperature score to be true to these said by Sea to Summit. Every sleeping bag fashion from the Sp1 to the Sp4 has been examined to EN requirements so you possibly can relaxation assured that the sleeping bag will preserve you heat on the temperatures as reported.

I’m usually a chilly sleeper except I eat a really heavy meal earlier than going to mattress (which might preserve you hotter at night time). I’m a aspect sleeper on the whole and I discovered the bag to work properly when sleeping on my aspect or again.

It’s tremendous essential to notice that there are 3 temperature rankings listed on every sleeping bag.

Consolation Ranking

The Consolation Ranking is a very powerful score as that is the temperature at which you’ll be heat and may sleep properly. Sadly, the sleeping bag business as an entire fails to make use of this score for advertising causes. However use this as your base for what bag will preserve you heat at what temperature.

That is often the temperature at which a lady will sleep properly with out being chilly.

Restrict Ranking

The Restrict Ranking is utilized by nearly all sleeping bag producers because the temperature score for the sleeping bag. Few folks will get an excellent night time’s sleep on the restrict score except you realize your physique properly sufficient to know you’re a heat sleeper. I do know myself properly sufficient to know I’m often midway between the Consolation and Restrict Ranking for my very own private score on how heat I might be at night time inside a bag.

That is often the temperature score {that a} male, curled up on his aspect, will sleep. Most individuals will really feel chilly and never sleep properly when sleeping on the restrict score temperatures.

Excessive Restrict

The Excessive Restrict is the restrict inside which individuals won’t die from hypothermia or excessive chilly. You may be assured that for those who use the bag on the Excessive Restrict you’ll stay awake in any respect. If going into the Excessive Restrict you should definitely get a Thermal Sleeping Bag Liner and even higher improve to a 4 Season Winter Sleeping Bag.

Dimension

As talked about above the sleeping bag is snug and designed as an expedition dimension. This lets you put on layers of clothes if wanted whereas contained in the sleeping bag. Subsequently, the Spark Sleeping luggage have greater inner dimensions than most ultralight mummy-style sleeping luggage.

Caring in your Spark Sleeping Bag

When you may have a high-quality sleeping bag it’s value taking care to take care of it. Probably the greatest issues you are able to do is put on clear backpacking base layers to mattress to stop sweat, grime, and physique oil from penetrating the liner of the sleeping bag. You can too use a sleeping bag liner to maintain it clear.

Tips on how to retailer your Spark sleeping bag

The Sea to Summit Spark comes with a Lofting bag included along with your bag. The lofting bag will not be as giant as I would really like. A few years in the past Sea to Summit Sleeping Luggage got here with a really giant cotton lofting bag. I’d have preferred to see a bigger lofting bag at the very least twice the dimensions of the one provided.

Like most individuals, I typically go weeks and months between mountain climbing journeys or bikepacking journeys into the backcountry. Whereas not utilizing the sleeping bag I’d like to have it saved in a big lofting bag. Possibly that’s one thing that may enhance sooner or later. Having stated that, the lofting bag is such a minor criticism that I can overlook this when making an allowance for the general high quality of the sleeping bag and every little thing else provided with the bag.

Tips on how to wash your Spark Sleeping Bag

Over time the sleeping bag will lose a little bit of its loft and you might begin to complain that the bag is inferior to it was. Possibly it would begin to have some funky smells that appear to be a cross between a sweaty health club and an unwashed homeless individual. If this happens it’s time to wash the sleeping bag. I wrote an article on how to do that so check out Tips on how to Wash a Down Sleeping Bag, for additional particulars on easy methods to wash your bag.

Value

The Sea to Summit Spark is a premium Sleeping Bag at a premium worth. Having stated that, they don’t price as a lot as among the different premium ultralight sleeping luggage available on the market in the meanwhile. The Spark Vary sits on the larger finish of the worth vary in comparison with the opponents however that larger worth comes with usually higher availability.

No want to hitch a waitlist or look forward to the luggage to be made like some ultralight corporations.

Sea to Summit Spark Vs The Relaxation

How does the Sea to Summit Spark evaluate to different Sleeping Luggage within the ultralight class in 2025. Take a look at my full comparability assessment of the Sea to Summit Spark and all of the Greatest Ultralight Sleeping Luggage 2025.

Greatest Suited Use

The Spark Sleeping Luggage can be excellent for anybody who’s sleeping in temperatures above freezing or beneath within the case of the Spark 0F. The next varieties of journeys can be excellent for this bag.

• Summer season mountain climbing within the Rockies or Sierra or North America. Or into the Spring and Fall if utilizing the hotter Spark 15F and Spark 0F.
• Summer season mountain climbing within the Alps in Europe or mountain climbing the Camino. The hotter luggage might be properly suited to three season journeys in most locations.
• Summer season mountain climbing and 3-season mountain climbing in Australia and New Zealand in most areas.
• Summer season journeys in South America together with Patagonia so long as the nighttime temperatures are above freezing. You could want the Spark 0F or one thing with extra insulation if heading to the Excessive Andes of Bolivia, Peru, and Ecuador.

Conclusion

The Sea to Summit Spark is finest suited to anybody wanting a high-quality ultralight sleeping bag. The temperature score for this bag is true to the specification in my view and primarily based on my use of the sleeping bag.

In order for you a sleeping bag for the summer season months and into the shoulder season for hotter climates then that is for you.

Relating to enhancements, I want to see a lighter-weight cinch chord on the hood, overstuffing down on the hood, collar, and neck draft tubes, and a bigger lofting bag.

I ponder if they’re contemplating utilizing the next loft Ultrdry down sooner or later. Some producers are actually utilizing 900+ Extremely-Dry and 950+ loft. When you get that prime on the loft score the down turns into a little bit extra delicate and must be taken care of properly by the person. Simply my ideas.

Total, the Sea to Summit Spark vary of sleeping luggage is certainly one of my all-time favourite sleeping luggage in 2025. There may be little to fault, and people faults are so small that it isn’t sufficient to make the bag something lower than among the finest available on the market.

Steadily Requested Questions

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