UKH

Hi everyone

I have a Sea to Summit Flow 35L  roll top backpack which for the most part is 100% waterproof - except for the 2L external zipper pocket . Iam  finding it extremely difficult to find a similar waterproof backpack but approx twice the size at least 50L  to  100L  maybe, only water resistant packs (DWR) that maybe you have to put a rain cover on  and/or the bottom of these larger packs are not waterproof and gear gets wet. Is there anything on the market similar to the sea to summit flow but larger capacity, any help would be much appreciated.

I have a Gul 100l which I picked up cheap, it's OK but I don't like the fastex type buckles, they seem a bit fragile.

Ortlieb seem to do better quality bags, which was my first choice. 

I went for an unplanned sea swim with my Arcteryx Alpha FL40 and it kept everything dry, though I don't think it's sold as a dry bag.

For true submersible backpacks I believe Watershed are the best there is (I've never used one personally). This one seems to match your requirements: 

https://www.drybags.com/product/westwater/

Lomo do a 60 litre one: https://www.lomo.co.uk/products/60l-dry-bag-rucksack-black/

At the risk of teaching you about the eggg sucking, you could just buy a large drybag ruckcack liner and use a normal large bag, which would then give you the benefit of a better back system, features etc. I use an Osprey one which has kept out some frankly awful weather on multiday trips or Lakes winter climbing.

Crux packs are totally waterproof but very expensive. I've got an AK47-X which I got second hand from someone on here - its a great climbing rucksack but I certainly wouldn't pay full price for it. They do 57l and 70l versions too.

The above!!!

That's the only way you're going to get it waterproof and it'll be lighter and better solution than trying to get a 100% waterproof rucksack (inevitably it'll be for canoing or something and totally sub-optimal for hill walking etc). Get a dry bag for the stuff the has to be dry

https://ultralightoutdoorgear.co.uk/drybags/

This is 45 ltrs but they might make a slightly bigger model. Lots of room in this one though - it feels like a big 45. https://www.ukclimbing.com/gear/rucksacks/medium/ortlieb_atrack_pack-14698

Great , the Cruz 70L AK47,  that looks like the one either secondhand , or save a while for a new.

I'd have thought cavers & canyoneers would be the people needing waterproof bags most, what's available for them? Otherwise drybag in a normal bag seems the best idea.

Its an idea, but why not have a backpack where no water can get in? , if you need to put further dry bags inside your rucksack - then to me that means it leaks so must get heavier? 

Try Lomo - they do dry bag sacks of all sizes - cheap.

Cavers don't use waterproof bags due to the waterproofing failing within a couple of trips. Once the waterproofing has failed, when you drag it through a wet crawl or duck it'll fill with water and become obscenely heavy. To avoid the bags staying filled with water caving tackle sacks actually have holes in them at the bottom for drainage. To keep things dry cavers rely on daren drums, waterproof boxes and dry bags. 

Don't know if this is helpful but the fact that cavers who crawl and swim through water don't use waterproof bags but just keep dry inside the bags is an interesting argument for the futility of waterproof bags.

I am a full-time WML, and though I agree with those that say use drybags to keep your kit dry, the real issue comes with having to go out day after day with a soaking wet rucksack that has absorbed water into the hip belt and back pads etc.

It's fine if you have the time and space to dry the sack well, but it really can be a pain if the next day is dry, but you are damp from your wet bag. 

Also, I sat in my campervan a lot, so the drying issue is all the more important.

To that end, I bought a Crux AK47-X, and it is absolutely my default sack for winter, or any time I know that it is going to be predominantly rain, (which seems to be constantly right now!) I would say that it can be sweaty on your back if you run hot as I do, hence my colder-weather use, but it is bombproof, which I like. If you like pockets, mesh and bells and whistles, it's not the sack for you. I made a wee pouch that hangs from the hipbelt for my compass and odds and sods, otherwise it is clean and non-fussy.

The only really odd thing is that the website said 'hydration compatable', yet when it arrived, the lid has a slot for a tube, the sack has an inner pouch, but the roll-top doesn't have an exit point for the tube. I rang Carol and asked him why, and he said that people had asked for the floating lid, but he hadn't had chance to alter the descriptions! I made my own hole using a tarp cleat, and at exactly 1cm, it allows the tube through, but no water ingress, result!
I notice now that none of them seem to have hydration bladder capability in the AK range, so that would be an issue for me, otherwise it's an excellent sack. I do notice that they have gone up in price a hell of a lot in just a couple of years though....an awful lot!!!

And if your bivvy beers puncture inside your sac floods everything else causing a major sense of humour failure ...

Thanks , your post has answered most of my questions, especially about the hydration bladder capability

My Crux AK-57 has been my default rucksack for the past 10 years... whether that's for winter climbing, ski touring (when not dragging a pulk) or multiday hiking/camping up to a week self supported (anymore and I'm tight on space with the food requirements).

Apart from a broken plastic buckle, it's been flawless.  Not mega comfortable, but light AF and practically waterproof (the new roll top ones being even better, but no top pocket).

Never again will I go for useless side pockets, non-kevlar material or a something that needs a separate rain cover.  AK all the way, baby!

As Colin Ford said, for people who habitually get into wet conditions, you need drain holes in those bags to let the water out, not try to make them water tight.

In a similar manner, if your oversuit (cordura boiler suit, usually waterproof for warmth) makes a tight fit over the top of your wellies (so lifting  your heel to backside to drain  them doesn't work, and over top of wellies not inside so they don't fill with mud/gravel on during crawls) you need to drill small holes in the wellies insteps to let the water fall out (and wear wetsuit socks), sometimes you don't even want the wellies to be waterproof 🤣. Same kind of principles with the caving bag +dry bag.

Dry bag, or as Colin said a Daren Drum if it's seriously  wet. Spelled with only one "r" as it's named after some caves in Wales not a person called Darren   https://starlessriver.com/product-category/dry-bags-daren-drums/ 

My preference is for multiple dry bags. Using different dry bags help keep your rucksack organised - one bag for food, another for emergency kit (first aid, bothy bag, etc), and another for spare kit (spare gloves, hat, buff, etc) and so on. Using different coloured dry bags reduces the amount of faffing when looking for something. 

The important questions no one has asked is what are you using it for? For multiday trips or day hits where you need to keep spare layers/gloves dry then a dry bag is fine. For actual submersion then look at bags designed for wet activities, although they never carry very well. If you're not using it to carry yourself, or you have really crucial kit then there are always barrels.

I have a small 8l Curver keg for canyon/coasteering work to keep my phone and FAK dry inside a roll top waterproof Lomo bag. For Scottish winter walking/climbing/mountaineering work I just use a normal rucksack (ME Tupilak) and have everything which needs to stay dry in a dry bag. 

The problem with carrying a mostly waterproof bag is that they will at some point fail and you end up with a really heavy bag carrying lots of water! 

Multiday trips. In the past ive used a large rucksack (think it was around 90L) and at the end of day 1 everything inside was wet through - and no doubt the pack was much heavier, so Iam now thinking none of that is going to happen again, heavier pack even with drain holes so basically they leak through and everything gets wet unless youve further dry bags. I get the idea of multi dry bags of different colours maybe for organization,  but I suppose you can use that idea in a more waterproof pack also.   

https://www.amazon.co.uk/Earth-Rucksack-Waterproof-Backpack-Cushioned/dp/B0...

Comes in several sizes.

I believe ortovox do a range and they're good quality. A friend has the non waterproof version and they are well constructed.

The main problem with waterproof packs (as far as I can tell) is that they eventually end up with holes in them, and then the water gets in and can't escape. They're then hard to dry out, heavy to carry, and everything inside gets wet anyway. 

Despite doing ML and WML training/assessments in the worst wet weather imaginable and working outside many days a year whatever the weather, I've never felt the need to have a waterproof bag. 

Primarily because the carrying system tends to be a bit rudimentary and they're generally not nice to carry for any distance as a result (especially whilst heavily loaded).  Obviously that's only a problem if it's what you intend to do.

For either a big drybag or smaller ones to pack inside a 'normal' rucksack, I'd echo the recommendation to look at Lomo.  They're very much like an aquatic Alpkit - they make good quality stuff at the cheap & cheerful end of the market mostly, usually not the best kit you can buy but frequently the best value for money and more than good enough to do the job.

A few years ago I bought an Osprey chest rig and as soon as it rained that was it everything was wet inside , as clearly they are not waterproof either, for that I bought one of them plastic waterproof shower caps that some people wear , that seem to do the trick . But I think this type of equipment  should be made without faffing about about and putting covers on and/or  extra dry bags. Theres got to be a market for a backpack for multiday hikers/mountaineers that is waterproof (made with drain holes- if need be ) , much better than something water resistant which to me means it leaks.  

As others have mentioned, the issue with a waterproof rucksack is that they are expensive to make (taping seams etc) and once you've worn a few holes in them, aren't anymore but are still expensive.

The other issue, especially on multi day walks is that, if you are operating out of the pack in constant rain conditions, every time you open it or put wet kit back in you are introducing moisture inside the bag.

Having separate dry bags for spare clothes, sleeping bag etc really takes a lot of stress out of being in bad weather as at least you know that once you hit your tent you'll have warm dry kit to wear and a decent night's sleep.

Rain covers are good to keep mud off rather than any real protection.