Helikon Arid Dry Bag
One of the most important things to do whilst in the wilds is keep your kit dry. Don't believe the manufacturers garb about their rucksacks being 100% waterproof as, from many years of experience, water finds its way in in the the worst conditions.
Compartmentalising your kit is also a really good idea so instead of packing everything in one 100 litres dry bag pack everything in smaller bags. This makes finding things easier and there is also less risk in getting kit wet. The best way is to put your sleeping bag in one bag, you socks, t-shirts & underwear in another, warm layers in another and so on. That way you will not be unpacking your sleeping bag in a downpour to get to a warm mid layer.
The Arid Dry Sacks are made of lightweight, coated fabric that will help you keep all your precious thing dry. Glued seams and tight roll-top closure prevents any moisture getting through and they available in 2 sizes and colours.