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How to Keep Kit Dry with Drybags – Tip #66

By 30th October 2021February 12th, 2023Resources, Summer, Tips, Walking, Winter, Winter Walking


This month’s tip is all about how to keep kit dry with drybags. First I’ll look at a couple of ways that many people use but which have huge drawbacks. Then I’ll move on to the more effective methods.

Relying on the Rucksack to Keep Kit Dry

Some people believe, rather naively, that their rucksack fabric is ‘waterproof’ and will keep the contents dry. In the vast majority of cases, especially on designs with multiple zips, this simply is not the case. Generally speaking, rucksacks offer only a limited amount of water resistance which is completely inadequate in driving rain.

Some fabrics are more highly resistant to water and will keep a surprising amount of rain out. But they are still nowhere near ‘waterproof’. I would never suggest relying on this alone to protect vital items, such as extra layers of warm clothing.

A smaller number of niche products, often with rubberised materials and roll-top closures, are genuinely close to being ‘waterproof’ in foul weather. However, even these high-quality products suffer from a simple design feature which means your kit can still get wet. They all have a massive hole in them. At the top.

It’s all well and good having a superbly waterproof rucksack when it is closed up, but the moment you undo the lid to access something, the concept falls down. Wind-driven rain, snow, or spindrift will find their way in there and instantly soak the contents. Snow is particularly bad, because it easily blows and drifts in, and sits there ready to melt. The warm down jacket you had ready to put on when it gets cold is now no more than a soggy cloth.

Moral 1 – Don’t rely on the rucksack alone to keep kit dry.

Using Rain Covers to Keep Kit Dry

Another common tactic is to use detachable rain covers. These may be totally separate items or ones that are integral to the rucksack that you pull out of a concealed pocket when needed.

These are okay at keeping some of the rain off the rucksack. They are more suited to regions where there is a heavy downpour for a short period of time, for example in tropical areas. But in areas such as the UK mountains where the rain is coming at you horizontally in the wind, then they are much less effective. The wind has a very good way of making sure that rain can get up and under any covers you may have in place.

High winds are very good at blowing these covers off and they quickly go through a lifecycle of raincover to kite to litter. For this reason, they are almost entirely useless in typical Scottish winter conditions.

Every time you want to access the contents of the rucksack, you have to remove the rain cover, exposing the rucksack to the rain. When the lid is open, once again in comes the rain soaking the contents. When you are finished, the whole comedy of fitting the flapping sheet back onto the rucksack must be repeated.

Moral 2 – Don’t expect a rain cover to be much use in combined wind and rain.

Using a Single Drybag as a Rucksack Liner

Another tactic is to line the inside of the rucksack with another layer of waterproof material. This can range between the black plastic bin liner much loved by DofE groups, to a properly designed large capacity drybag.

At least this approach now offers a second layer of protection to vital items of clothing and kit. Whatever water penetrates the rucksack fabric or its openings will sit between the rucksack and the inner dry bag liner. This second skin keeps the kit inside properly dry. Or does it?

Once again, this meths suffers from a serious flaw. As soon as you open the rucksack and the large inner dry bag, then rains and snow can enter and soak the entire contents. So it isn’t all that effective after all.

Moral 3 – Even rucksack liners have a hole at the top to let rain in.

Using Multiple Drybags to Keep Kit Dry

This brings us on to my own preferred method which I think is hard to beat.

How to keep kit dry with drybags

Use multiple drybags, available in different sizes and colours, to separate and protect your kit in smaller individual packages. A larger dry bag can hold the spare warm duvet jacket, which is vital to carry even if you do not use it at all during the day anyway. Medium bags can hold things like the first aid kit. Smaller bags can carry spare gloves and other useful items such as a penknife or Leatherman tool.

The colour coding also makes it easy to locate each bag and hence each group of items.

With experimentation and practice, you will come up with your own system that works for you. But what is certain, is that each time you open the rucksack any incoming rain or snow cannot now come into contact with your dry kit.

In winter, a really good additional tip is to keep the ski goggles in a dry bag all of their own. This keeps them totally moisture-free until you need to wear them. (Putting on wet goggles leads to instant misting up!).


Keeping kit dry in your rucksack in bad weather is vital. But it takes preparation, the right tools and perfecting a ‘system’ that works for you.

  • Don’t rely on the fabric of the rucksack itself. These are generally not very water-resistant at all.
  • Even truly waterproof sacks are no longer waterproof when you open them up.
  • Don’t rely on detachable rain-covers. The wind will drive the rain underneath them, that is even if they stay on your rucksack.
  • A single waterproof dry bag liner works when it is closed. But as soon as it opened up the entrance hole lets in all the rain and snow.
  • The best method is to use multiple drybags, using different sizes and colours for different groups of items.