• Weight (regular) 1100 grams
  • Size packed 183 cm x 55 cm x 10 cm
  • Recommended Maximum User Height 183cm
  • Female Comfort Rating -4
  • Male Comfort Rating -10
  • Cost $699.99

Sea to Summit Ascent AcII Sleeping Bag Regular

Sleep Systems


Rating: 8.4 / 10
Weight 1.5 / 2
Value for Money 1.7 / 2
Durability 1.7 / 2
Warmth 1.7 / 2
Versatility 1.8 / 2

Sea to Summit Ascent AcII Sleeping Bag Regular Review

Unless you only ever sleep in one particular climate where the temperature never changes, your sleeping bag of choice is going to be a compromise (unless you own multiple bags). If you only want one sleeping bag then you need one that will take you down to colder temperatures than you usually camp in. There really is no one perfect sleeping bag and with so many sleeping bag options on the market these days it can be confusing. Certainly the dominant player on the Australian market at the moment is Sea to Summit which provides a range of bags from the basic to the top end. I need to be upfront here and state that given the amount and type of hiking I do, I will always go for the top end (more expensive) bags but this often means spending well over $600 on a bag but I know from discussion with both the suppliers and a number of hikers that this segment of the market is not where the majority of hikers sit.This is where the Sea to Summit Ascent AcII Sleeping Bag comes in. The RRP of this bag at the time of this article is $699 and as such sits in the middle of the Sea to Summit range and while not the smallest bag when packed it is on the smaller end of the range. Sea to Summit promotes this bag as:

‘Light, warm, comfortable and most importantly, adaptable. The Ascent™ is our sleeping bag of choice for most adventures, most of the time.’

So let’s look at what this bag does. Firstly this is a down sleeping bag which contains 750+ loft down. This ethically sourced down sits between the cheaper 650 loft and higher quality, more expensive 850+ lofts.  Most manufacturers are using a water repellent down these days and Sea to Summit use what they call ‘Ultra Dry Down’ which means that if the bag does get wet, and by wet we are talking about condensation and sweat, it still provides a high degree of warmth. After using this in mid winter and at a period where we had sub zero temperatures as well as a high moisture content (which meant that the apparent temperature was on the very cold side) I have to agree. This bag is rated at being comfortable at -10°Celcius for an average male and -4°Celcius for the average female. This range will cover me in just about any hiking I do although my wife Gill prefers a warmer option which is not unusual for most females. One thing I would say here is that in Sea to Summit’s latest range of bags they have split the bag in two in regard to the down baffles – the upper half of the bag having horizontal baffles and the lower half having vertical baffles that keep the down where it belongs and thereby keeps you warm when you need.

This bag is well constructed and looks to be durable. In the latest range of bags Sea to Summit makes the bag colours darker as they become warmer so in this case the bag is a mid green colour. Shape wise the bag is a tapered rectangular construction which means it has more space than the ultralight mummy bags but not as much space as the fully rectangular shaped options. In practice this shape provides a compromise but one that I found it to be quite comfortable although the bag I tested was the regular length bag which is recommended for hikers up to 183 cm in height. At around 186 cm in height, and with large feet, I was a bit jammed in this bag but would expect to be quite comfortable in the longer version which suits hikers up to a height of around 198 cm (6’6″). Weight wise the regular length bag weighs in at 1100 grams which is by no means a lightweight bag however when packed down it does compress to 3.3 litres in size which is reasonably small. Similar bags that use a lesser quality down will weigh more and take up much more space in your pack.

The bag has three zips. The right hand side of the bag has a half zip while the left side has a full length zip and also a small foot pocket zip that allows you to adjust the zip options to let in the right amount of air to too cool down when the weather gets too warm by unzipping a little or all the way. You can keep one arm or two out of the bag, in really hot conditions open up the foot pocket up for minimal warmth. This versatility is something that the high end/low weight bags will often sacrifice to save weight. The hood on this bag is luxurious and given my lack of hair something I appreciate in the colder conditions.

There are a number of other features on this bag that are worth considering. There is a small internal security pocket but rather than storing valuables I prefer to keep my battery pack or phone in to ensure that it maintains charge in the cooler weather. A series of oversized draft tubes are present along the zips and around the neck which minimises air flow and keeps you warm during during the colder weather. And last but not least these bags can be joined to form a couple’s bags which is something I have yet to try. As much as I love my wife and she loves me, we prefer separate bags. But you may choose otherwise.

The Sea to Summit Ascent Bag comes in lighter weight and heavier weight versions depending on your warmth requirements. All in all, the best way to describe this bag is as a ‘Goldilocks bag’; Not too hot, not too cold, and just right. If you are looking at a one size fits all bag that will meet most of your needs without having to use multiple bags as well as not breaking the bank then this bag is a great option. If you dont have to carry this bag in a pack then wight probably isn’t going to be a consideration making this bag a great choice for car campers.

We Like

  • Tapered rectangular shape minimises airflow but provides just a bit more space in the foot box for those with bigger feet providing a good balance of space and warmth
  • Lightweight 20D Nylon shell which reduces the minimal packed size but provides durability
  • 750+ Loft ULTRA-DRY Down that provides good insulation and keeps the packed size reasonably small
  • A combination of vertical chest baffles and horizontal lower body baffles that keeps the down in the right places to prevent cold spots
  • Half right side zip, full length two-way left side and separate foot zip for freedom of movement, increased ventilation and dual-use as a quilt. This is a very versatile bag
  • Oversized draft tubes with anti-snag materials, prevents heat loss through zipper and around the neck
  • A luxurious hood and dual cord adjustment for maximum warmth retention
  • Internal security pocket to keep track of valuables or to keep you phone warm on those cold nights
  • Zip Coupling: This bag is designed to pair with another if you are into that although I have never seen anyone do it on the trail
  • Great value sitting at the midpoint price wise

We Don't Like

  • As a hiker who likes to go lightweight and compact, at 1100 grams I find it a bit heavy and bulky. For the average hiker this may not an issue

Best Uses

  • A great ‘Goldilocks sleeping bag’ for those wanting just one bag to do everything and aren’t focused on the lightest bag available

Buy One

You can purchase the Sea to Summit Ascent AcII Sleeping Bag from Snowys, Wild Earth, or from Wildfire Sports

Disclosure:  We may earn a small commission, at no additional expense to you, if you click through and make a purchase. Please note that our affiliations do not influence, in any way, the independence of our reviews. If we don’t like a product, you’ll hear about it from us!


AUD $699.99 RRP. Keep an eye out for the regular sales that occur and you may get a great deal

Other Versions

  • The Sea to Summit Ascent AcII Sleeping Bag is also available in a long size to suit people up to 198 cm. If you are taller than 183cm then move up to the ‘long’ version of this bag
  • There is also an Ascent I and an Ascent III for those that want a lighter weight/heavier weight bag

Sea to Summit Ascent II sleeping bag

Sea to Summit Ascent II temperature ratings. This bag will suit the ‘average female’ down to -4° and the ‘average male’ down to -10°

Bags joined together. If you are doing this you will have to choose bags that are designed to join together. Please note in this image the smaller female bag in the centre of the image

1 litre water bottle up against the sleeping bag in its compression bag

Close up of storage bag and 1 litre water bottle with the compression sack on top. Never store your bag long term in a compression sack

Close up of the toe box with a small zip at the base that allows you to let cool air in on those warm days

Ascent II Hood

Right hand side half zip. The zip on the left side of the bag is a full length zip

Close up of zip and two neck draw cords

Security pocket on the inside of the bag. I use this style of pocket to store my phone or battery pack in cold conditions to maintain the battery life


This review was done with product provided by Sea to Summit for testing

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