• Capacity 70 Litres
  • Weight 98 grams
  • Size 51cm x 20cm x 90cm
  • Colours Various colours
  • Cost $49.99

Sea to Summit 70 Litre Ultra-Sil Pack Liner


Rating: 9.2 / 10
Value for Money 2.2 / 2.5
Versatility 2.3 / 2.5
Weight   2.4 / 2.5
Durability 2.3 / 2.5

Sea to Summit 70litre Ultra-Sil Pack Liner Review

The first question many people ask is why bother to use a pack liner? Surely a pack cover will do the job and keep the rain out of my pack? Maybe!

My best response is by way of an experience relayed to me by another hiker I came across last year. This hiker was undertaking a two week long trip and due to recent heavy rains had to traverse a gully on the Larapinta Trail that involved him wading in water almost up to his chest level. He held his pack up above his head but part way through the crossing dropped his pack into the water. He quickly managed to retrieve the pack but not before it had submerged. While the majority of his gear managed to survived, albeit a little damp, his SLR camera wasn’t so lucky. Even worse it wasn’t his camera, he had borrowed it from a friend.

In this instance a pack cover which is designed to keep rain off the pack wouldn’t have helped. The other issue with pack covers is that in torrential sustained rain they will not usually prevent water entering your pack as the water will run down your back and soak in through the pack from the outside in.

For me a pack liner is a non negotiable piece of equipment on all overnight hikes as well as those day hikes where I am expecting rain or know that I have watercrossings. If used correctly they will prevent water entering your pack, not only preventing your expensive bits of technology such as cameras, phones and iPads from getting wet but also ensuring you have dry clothing and sleep gear at the end of the day.  In addition to providing a waterproof layer, these pack liners also provide protection from fine dust and grit which is all too common in arid Australia.

These pack liners come in three sizes; 50 litres, 70 litres and 90 litres and you match the dry bag size to the corresponding pack size. A word of warning here. If you have a full 5o litre pack and a 50 litre pack liner, you may well be cutting it fine with the roll top closure. As it sounds, the roll top needs to roll over to provide the water protection and if the dry bag is overly full then you won’t be able to get a complete seal. I am currently using an Ospey Atmos 50 Pack (53 litres capacity for the large size). When my pack is full to the brim for a long trip, the 50 litre dry bag is not quite large enough so I will usually use the 70 litre size to ensure that the top is rolled over enough to provide a decent water proof seal.

I have been using this dry bag for over 12 months now and while I haven’t dropped my pack in the river, I have been through some periods of torrential rain and at the end of the day everything inside my dry bag is bone dry. Now I’ll fess up here and say that I also pack all my gear within my dry bag into smaller Exped Zip Packs. While I mainly use these smaller packs to keep my gear organised they also provide an extra layer of waterproofing. This means that in the unlikely event I do have to get gear out when its raining there is minimal risk of everything getting wet.

Some ultralight hikers will use heavy duty garbage bags but these have to be replaced regularly as they don’t last that long and you need to keep an eye on the wear because they can fail with little notice.

I can’t stress strongly enough how important pack liners can be. For the minimal weight addition and small price addition (compared to your expensive water sensitive gear) this is one item that  is well worth the outlay.

Sea to Summit 70 Litre Ultra-Sil Pack Liner, green

Sea to Summit 70 Litre Ultra-Sil Pack Liner with the bag mouth folded over ready to close

Clip system

The top rolled down to provide a waterproof seal

Sea to Summit 70 Litre Ultra-Sil Pack Liner inside the pack ready to fill

We Like

  • This pack liner weighs almost nothing so those ultra lighters amongst you will hardly notice the weight
  • Protect all you gear from getting wet be it the rain or dropping it as you cross a stream
  • Seam sealed to protect your gear from the wet
  • Protect all you gear from getting covered in the fine dust that is so common in central Australia and other arid zones
  • Wide opening mouth so its easy to get the gear in and out
  • Roll top closure to ensure that water will need get into the bag
  • Shaped to easily fit into your pack ensuring maximum use of the available space
  • Various colours

We Don't Like

  • If your dry bag fills the pack then you can only access your gear through the top opening. This is only really a problem if you use a pack that has a bottom and top opening. Top access pack users won’t notice any difference

Best Uses

For hikes where rain, dust or river crossings are present. Oh wait, isn’t that most hikes?

Buy One

You can purchase the Sea to Summit 70 Litre Ultra-Sil Pack Liner online from Snowys

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!

If you have used the Sea to Summit 70 Litre Ultra-Sil Pack Liner or if you have questions, we’d like to hear from you. Post your comment or question below


AUD $49.99 RRP

Other Versions


This review was done with product purchased from a retail store by Australian Hiker

Australian Hiker Newsletter

* indicates required

Leave a Reply

Your email address will not be published.