Sea to Summit Ascent and Altitude Sleeping Bags – His and Hers Ultralight Down Bags

The new Sea to Summit Ascent and Sea to Summit Altitude sleeping bags mate together and have water-resistant down to keep you dry in wet situation.

The Sea to Summit Ascent (men’s) and Altitude (women) sleeping bags are high quality, 2.5 season water-resistant down bags that can be mated together to create a 2 person sleep system. They are very lightweight and packable.  Suitable for backpacking in various conditions.

750 Fill Water Resistant Down

Using 750 Fill down that has been treated to be very water-resistant, you can use these down bags in wet conditions. Meaning, condensation from within your tent or van will not be disastrous with these down bags. The 20D material does a great job of being soft against the skin, as well as keeping the down in the bag.

I really like that Sea to Summit also includes a great storage bag.  It is not something you may think about when you are looking for a sleeping bag, but it is very helpful. Think about it, the sleeping bag is probably going to be stored more than it is going to be used. So why not have a great storage bag?

Great storage bag

The storage bags allow for modular storage in a closet or gear crate.  Most storage sacks are large cotton bags that take up a lot of room.  Heck, our garage has a half dozen sleeping bags hanging off one hook! LOL

Enough about the storage bags, lets talk about the actually sleeping bags!  My wife and I used these bags over the summer and early fall here in Colorado.  They were good down to the upper 30s, no problem.  So, the 2.5 season rating feels accurate for us.

I actually used the bag inside quite a bit as well.  It was nice to turn it into a quilt and use it on the couch for snuggling up, or just napping. So, we appreciated the ability to open the bags all the way up.

The bags also come with a legit compression bag made of Ultra-Sil.  This is a very good compression bag that does a great job of compacting and protecting the bags.  Made of Cordura fabric and smooth to the touch, making stuffing the bag inside easier.

Sea to Summit Altitude – Women-specific sleeping bag

Sea to Summit built the Altitude specifically for women.  With more insulation in the chest and feet and extra room from the hips to the knees.  You can see this in the pic below.  They added THERMOLITE in the footbox to speed up the warmth as well.  That is on top of the super nice 750+ fill Ultra-Dry Down.  My wife was impressed!

Mateable sleeping bags

When we camp together, we always use a 2 person sleeping bag.  It just makes sense for us and our dogs.  Usually one of the dogs sleeps in the bag with us too.  The Altitude and Ascent can zip together to make one big bag.

Though, your feet will be separate as it still retains a bit of the mummy shape.  This can be a benefit for foot warmth, but a drawback if you like to play footsies LOL.  All in all, the mated bags do a good job of keeping the heat in and keeping close to your partner.

The models we tested were the men’s 35 and women 25. We used them in conjunction with the Sea to Summit Comfort Deluxe sleeping pad (full review here)

Altitude Sleeping Bag $379 – https://snp.link/dd5bf667

Ascent Sleeping Bag $449 – https://snp.link/88fceb6f


Ascent Down Sleeping Bag (25°F, 15°F & 0°F)