In 2019, Sea to Summit re-worked their entire range of Sleeping Bags leveraging on their in-depth knowledge and understanding of the sleeping bag market to deliver a range defined by technical performance, comfort and versatility.
Sea to Summit 2019 sleeping bag technologies include:
- New Free Flow zip design incorporates both full and half-length zips in the same bag for temperature adaptability.
- New zip coupling system where all bags identified with this feature are produced with the same 165cm #5 YKK zipper, allowing any left zippered unisex bag to be joined with any right zippered women’s bag.
- Updated fabrics for technical performance.
- Superior ULTRA-DRY down™ that almost eliminates the negative effects moisture has on down.
- A ‘Down Batch Test Report” International Down Feather Laboratory (IDFL), the world’s largest and most respected down laboratory enclosed with every bag.
- Responsible Down Standard (RDS) Certified to ensure humane sourcing of down.
- WaveLoft™ construction in the synthetic bags that loops thick layers of proprietary THERMOLITE® insulation together for extra loft and warmth.
- Warmer women’s specific engineering with a modified shape, extra down and thicker footbox insulation.
- Temperature tested to the EN13537 European standard for sleeping bags. (excludes Ember quilts)
With 42 sleeping bag variations across 16 different models, there is truly a Sea to Summit sleeping bag to suit every user on any adventure.
Based on our first impressions we’ve summarised the range below and you can find all the juicy specifications by clicking on the links through to our product pages.

Alpine (ApII, ApIII) UPDATED IN 2019
The most technical sleeping bags in the Sea to Summit range. The Alpine bags are a mummy shaped bag loaded with 850+ ULTRA-DRY Goose Down for extreme conditions. Waterproof NanoShell fabric protects the down, vertical chest baffles ensure warmth around the torso, expedition sizing caters for extra clothing and even boots to be worn inside, and one full and one half zip add a touch of versatility.
Technical features – 850+ Loft ULTRA-DRY Goose Down. Vertical chest baffles. Free Flow zip system. NanoShell Waterproof fabric. Expedition sizing to accommodate for extra clothing and boots. Cannot be joined with another bag.
Ideal for – High altitude and arctic expeditions.
Shop here – Alpine ApII | Alpine ApIII

Spark (Sp0, Sp1, SpII, SpIII, SpIV) UPDATED in 2019
The Spark bags are a lightweight and technical all-rounder for both men and women. There’s a version to suit every weight conscious explorer on warm weather adventures right through to cold climate expeditions. They feature 850+ ULTRA-DRY Goose Down and ultra-light fabrics and trimmings and vertical chest baffles combined with a contoured mummy shape for optimal lightweight thermal efficiency.
Technical features – 850+ Loft ULTRA-DRY Goose Down. Vertical chest baffles. Ultra-light 7D and 10D fabrics. Mummy shape for efficient insulation. Combination box and sewn through baffle construction. Cannot be joined with another bag.
Ideal for – Ultra-light adventures in warm to mid-winter climates.
Shop here – Spark Sp0 | Spark SpI | Spark SpII | Spark SpIII | Spark SpIV
Video – Spark review here

Flame (Fm0, FmI, FmII, FmIII, FmIV) NEW in 2019
The Flame is an ultra-light all-round women’s specific sleeping bag available in multiple versions to suit every activity. It has all the same materials and features as the Spark only with a women’s specific cut which is wider at the hip and narrower at the shoulder. Plus, it has a little extra down for increased warmth.
Technical features – 850+ Loft ULTRA-DRY Goose Down. Vertical chest baffles. Ultra-light 7D and 10D fabrics. Women’s specific mummy shape for efficient insulation. Combination box and sewn through baffle construction. Cannot be joined with another bag.
Ideal for – Women on ultra-light adventures in warm to mid-winter climates.
Shop here – Flame Fm0 | Flame FmI | Flame FmII | Flame FmIII | Flame FmIV
Video – Flame review here

Ember (EbI, EbII, EbIII) UPDATED in 2019
The Ember is a quilt, not a sleeping bag. The concept is that you save weight by using the mat you already have to insulate from underneath and the quilt insulates on top. They feature 850+ loft ULTRA-DRY down™ and super light 7D and 10D fabrics. Fast and light adventurers love the weight and space saved by taking a quilt, they are also a great ultra-light alternative to a sleeping bag for summer adventures.
Technical features – 850+ Loft ULTRA-DRY Goose Down. Vertical chest baffles. Ultra-light 7D and 10D fabrics. Sewn-through construction on EbI. Box baffles on EbII and EbIII. Sewn-in footbox on EbIII. Embers can be joined with press studs. Cannot be tested to EN13537 standard.
Ideal for – Fast & light hiking, cycling & travel in mild climates.
Shop here – Ember EbI | Ember EbII | Ember EbIII

Explore (ExII, ExIII, EXIII Double) NEW in 2019
A technical bag with a focus on comfort. The Explore is best suited to basecamp style adventures or car camping where you are not scrutinising grams and rucksack space. It features a roomy rectangular design filled with 750+ Loft ULTRA-DRY Down™, three zippers for multiple configurations including separating the top and bottom as a quilt and blanket, and a webbing system to attach a sleeping mat to the bag.
Technical features – 750+ Loft ULTRA-DRY Down™. Spacious. Vertical chest baffles. 20D and 30D fabrics. Panelled footbox. 3D Hood. Webbing to attach sleeping mat. Available in double size. Can be joined with other bags.
Ideal for – Car camping, van life, hut based adventures.
Shop here – Explore Ex ExII | Explore Ex ExIII | Explore ExIII Double

Ascent (AcI, AcII, AcIII) NEW in 2019
If you’re seeking a single sleeping bag to cover most adventures that offers a good balance between weight, durability and versatility, the Ascent is the right choice. These bags offer more space than a mummy bag and boast efficient design with vertical chest baffles, a panelled footbox and a 3D hood. The Ascent also features the Sea to Summit Free Flow zip design with both half and full-length side zips and a foot zip for temperature adaptability.
Technical features – 750+ Loft ULTRA-DRY Down™. Relaxed tapered rectangular shape. Vertical chest baffles. 20D fabric. Panelled footbox. 3D Hood. Free Flow zipper design. Can be joined with other bags.
Ideal for – Anything from car-based adventures to extended trekking in warm to cold climates.
Shop here – Ascent AcI | Ascent AcII | Ascent AcIII
Video – Ascent review here

Altitude (AtI, AtII) NEW in 2019
The Altitude sleeping bag is the women’s version of the Ascent and is a great all-rounder. It has all the same features only with a female-specific shape that’s wider at the hip and narrower at the shoulder. It’s also loaded with more down than the Ascent and features THERMOLITE® panels under the foot area for increased warmth.
Technical features – 750+ Loft ULTRA-DRY Down™. Relaxed women’s specific tapered rectangular shape. Vertical chest baffles. 20D fabric. Panelled footbox. THERMOLITE® panel underfoot. 3D Hood. Free Flow zipper design. Can be joined with other bags.
Ideal for – Women on car-based adventures or extended treks in warm to cold climates.
Shop here – Altitude AtI | Altitude AtII
Video – Altitude review here

Trek (TkI, TkII, TkIII) UPDATED in 2019
The Trek has been a staple part of the Sea to Summit sleeping bag range since the very beginning. The latest version has seen a change to vertical chest baffles for increased efficiency. The Trek has a tapered rectangular design that offers more room than traditional mummy bags and they come at a very affordable price for such a high-quality bag.
Technical features – 650+ Loft ULTRA-DRY Down™. Relaxed tapered rectangular shape. Vertical chest baffles. Durable 20D and 30D fabrics. 3D Hood. Can be joined with other bags.
Ideal for – General camping, hiking and travel.
Shop here – Trek TkI | Trek TkII | Trek TkIII
Video – Trek review here

Journey (JoI, JoII) NEW in 2019
The Journey is the Sea to Summit Trek bag only with a women’s specific design. Along with having all the same features that make the Trek a popular and affordable bag, the Journey has a shape that is wider at the hip and narrower at the shoulder. It’s also packed with a little more down and features a THERMOLITE® panel under the foot section for increased warmth.
Technical features – 650+ Loft ULTRA-DRY Down™. Relaxed women’s specific tapered rectangular shape. Vertical chest baffles. Durable 20D and 30D fabrics. THERMOLITE® panel underfoot. 3D Hood. Can be joined with other bags.
Ideal for – Women, general camping, hiking and travel.
Shop here – Journey JoI | Journey JoII
Video – Journey review here

Traveller (TrI, TrII) UPDATED for 2019
The Traveller is designed for, well, travel! It’s a featherweight sleeping bag with a minuscule pack size and a hoodless design that can be opened up as a quilt making it perfect for hostels or to throw over the top of another bag for added warmth.
Technical features – 750+ Loft ULTRA-DRY Down™. Tapered hoodless shape. Ultra-light 15D fabric. Sewn-through construction on TrI. Horizontal baffles on Tr2. Can be joined with other Traveller bags.
Ideal for – Travel
Shop here – Traveller TrI | Traveller TrII

Treeline (TlI) NEW in 2019
The Treeline is an entry level three-season down bag with a relaxed mummy shape and a single side zipper. It’s filled with a lesser lofting down and does away with the ULTRA-DRY feature to keep the costs down. Made with a 50D nylon shell, the Treeline maintains a quality lightweight build at an affordable price.
Technical features – 600+ Loft Down. Relaxed mummy shape. 50D fabric. Can be joined with other bags.
Ideal for – Kids or those seeking a durable and affordable down sleeping bag.
Shop here – Treeline TlI
Video – Treeline review here

Basecamp (BcII, BcII Double, BcIII) UPDATED in 2019
The Basecamp is the most luxurious synthetic sleeping bag from Sea to Summit. It is easy to care for and equipped with three two-way zips like the down filled Explore bag for ultimate versatility, you can even separate the top and bottom altogether. The Basecamp is warm and roomy but isn’t the lightest bag on the market so is probably best kept for general camping.
Technical features – WaveLoft™ THERMOLITE® synthetic construction. Roomy contoured rectangular shape. Multiple zipper configurations. Webbing to attach sleeping mat. Available in double size. Can be joined with other bags.
Ideal for – Car camping.
Shop here – Basecamp BcII | Basecamp BcII Double | Basecamp BcIII

Traverse (TvII, TvIII) NEW in 2019
The Traverse is the technical choice in the Sea to Summit synthetic sleeping bag range. The synthetic fill is easier to dry in the field and maintains better insulation when wet than a down bag (although ULTRA-DRY down™ is closing this gap). However, synthetic doesn’t offer the same warmth to weight ratio of down. The Traverse has a tapered rectangular shape and features a water repellent finish on the shell fabric. It also has the Free Flow zipper system with a half zip on one side and full zip on the other along with a foot zip for ultimate versatility.
Technical features – WaveLoft™ THERMOLITE® synthetic construction. Tapered rectangular shape. 30D DWR shell fabric. 20D Lining. Free Flow zipper design. Anatomically shaped footbox. Can be joined with other bags.
Ideal for – Cool weather adventures where there is a good chance your gear will get wet.
Shop here – Traverse TvII | Traverse TvIII

Venture (VtI, VtII) NEW in 2019
The women’s version of the Traverse, the Venture bag shares the same WaveLoft™ THERMOLITE® synthetic fill, 30D DWR shell fabric and Free-Flow zipper system, plus it comes with a few women’s specific design elements including extra width for the hips, narrower shoulders, and extra insulation in the footbox for increased warmth.
Technical features – WaveLoft™ THERMOLITE® synthetic construction. Women’s specific tapered rectangular shape. 30D DWR shell fabric. 20D Lining. Free Flow zipper design. Anatomically shaped footbox with extra insulation. Can be joined with other bags.
Ideal for – Women on cool weather adventures where there is a good chance your gear will get wet.
Shop here – Venture VtI | Venture VtII
Video – Venture review here

Trailhead (ThII, ThIII) NEW in 2019
Basic, affordable quality. The Trailhead synthetic bag from Sea to Summit offers space and comfort for general camping. It features a durable water repellent shell fabric and efficient WaveLoft™ construction as well as a single full-length zipper that enables the bag to be zipped opened as a quilt.
Technical features – WaveLoft™ synthetic construction. Tapered rectangular shape. 30D DWR shell fabric. 20D Lining. Single full-length zipper. Cannot be joined with other bags.
Ideal for – General warm to cool weather camping.
Shop here – Trailhead ThII | Trailhead ThIII

Quest (QuI, QuII) NEW in 2019
An affordable all-rounder for general camping and weekend warriors. The Quest is the women’s specific version of the Trailhead and features a shape that is wider at the hips, narrower at the shoulders and has a dose of extra insulation in the footbox. It has a single full-length zipper and maintains the quality build you can expect in all Sea to Summit sleeping bags
Technical features – WaveLoft™ synthetic construction. Women’s specific tapered rectangular shape. 30D DWR shell fabric. 20D Lining. Single full-length zipper. Thicker footbox insulation. Cannot be joined with other bags.
Ideal for – General camping for women in warm to cool weather.
Shop here – Quest QuI | Quest QuII
Video – Quest review here
What are your initial thoughts about the new sleeping bags from Sea to Summit?
About the writer...

Trekker, surfer, climber, mountain biker, runner, camper. Participator in most things… master of none.
Similar posts...
Thanks for this explanation, there are lots of choices and this can create some confusion.
My real question though, do you know why has the micro down 2 & 3 been discontinued?
Thanks again.
We actually don’t have a solid answer why the Micro Down range was discontinued, unfortunately, but it’s likely that it was a business decision based on sales. The Spark bags are probably the most similar in Sea to Summit’s current range of that helps, Roger.