BIVVY BAGS

Before we start let's first break down bivvy bag users into what I think are the five main types.

THE EMERGENCY USER

This person has bought a bivvy bag in order to have somewhere safe to sleep if they get injured or benighted. They have shelled out 100 notes and now carry the bag as some kind of insurance against injury or benightment.

THE MULTIDAY CLIMBER

This user needs to sleep out in order to get his/her routes done but can't afford the weight of a tent. He or she may also be forced to spend the night on ledges so small you'd have trouble balancing your cup of tea on them, let alone sleep on them.

THE SOLO BACKPACKER

This user likes the freedom of just sleeping wherever they want, just lying down and going to sleep, whether it's in a camp site or a field full of cows.

THE SCUZZY CLIMBER BUM

This user can't always be bothered to get their tent out, preferring to just rough it, be it in their car, in a bus shelter or in a car park - also known as a dosser.

THE TRAINED KILLER

This user generally dresses in green and lays down were he/she is told and usually sleeps with a gun. (Not to be confused with farmers.

BIVVY BAGS - DO YOU NEED ONE?

THE EMERGENCY USER?

The answer is NO, which I know will upset all those users who've been carrying a kilo of Gore-Tex around in their 'sacks for years. Have you ever got into your bag in the middle of a storm? Did it work or did you find that you froze your ass off, got miserable and lonely and then, when close to hypothermia, decided you'd prefer to die on your feet? The re-emergence of the bothy bag is a revolution in mountain safety and, I think, anyone who doesn't carry one in a group is missing out on both a real life-saver and a great place to eat dinner. Inside a bothy bag you're all together, sharing warmth, friendship and bad jokes. Things don't seem so grim, in fact, you can even get some sleep. If you're going to use your bivvy bag then couple it up with a bothy bag for real emergency protection.

THE MULTIDAY CLIMBER?

Maybe; instead of blindly taking that bivvy bag have a look at the alternatives. On a multiday rock route do you need 800g of Gore-Tex? How about a one season synthetic bag or Blizzard Bag matched up with a bothy bag? On a winter route do you need a totally waterproof bivvy bag? How about a water resistant bag half the weight? Do you need one inside a tent? If your sleeping bag has its own water-resistant shell then maybe not, or how about just a light cover rather than a full-blown bag? Several times over the last two years I've used my synthetic bag in the open in winter without any bivvy bag at all, relying instead on the bags DWRed outer shell and using my home made bothy bag if things got bad.

THE SOLO BACKPACKER?

No; the problem with a bivvy bag is that you can't do anything within one apart from sleep. Get caught out in stormy weather and you can't cook and just try getting into your dry sleeping bag in the rain without getting it wet. Hooped bivvy bags are often bought by these users, but unless they're proper mini tents (like the Outdoor Designs Racer), they're even worse than a bivvy bag, being just as useless but heavier and more costly. For this user the best bet is either a single person tent (warmer, bigger, bugproof and a joy to live in), or if weight and pack size is important then just take the fly sheet (Macpac Microlite fly for example).

THE SCUZZY CLIMBER?

Yes; the average scuzzy climber will probably get a great deal of use out of a bivvy bag, but doesn't necessarily need to buy a full spec bag. A sleeping bag cover would probably do most climbers.

THE TRAINED KILLER?

Yes; (because I don't argue with people who sleep with guns).

WHAT'S ON THE MARKET

PLASTIC BAGS

Loved by Boy Scouts, Duke of Edinburgh Award chasers and those too cheap to shell out for a proper sledge. Unless you plan on spending more than one night out in one then avoid the heavy brick-sized bags. The lightweight bags made by Lyon Equipment (and sold through most good retailers), are best. The plastic bag might save your life - but after spending a very, very, very long night in one you'd probably prefer a quick cold death instead.

FOIL BLANKETS

Good at keeping the juices in - if you're a chicken.

THE BLIZZARD BAG

Price: £25 Weight: 350g

The Blizzard Bag gets its own category here as there is nothing else on the market like it. When I first started writing for High I wrote about these bags just as they were coming on to the market, championing what I thought was a classic piece of British design. They aren't easily pigeonholed, being part bivvy bag, part sleeping bag and part survival bag, which I think has counted against them. At the time I thought that thousands of people out there would be looking for a product like this, but it seems so far only the specialist shops, instructors/guides and the emergency services have switched on to them (or even know they exist). So in order to do my bit for UK industry I'm going to write about the Blizzard Bag again (you may have noticed I've not covered the same topic twice so far).

Firstly the Blizzard Bag is not a glorified foil blanket or poly survival bag. It is a lightweight sleeping system for those of us who need the minimum to do the maximum (those in trouble, adventure racers and Alpinists). The bag is vacuum packed for storage (0.7 litres) and weighs in at only 330g, is 100% waterproof and windproof, yet provides the warmth of a regular two to three season sleeping bags and is tough and tear resistant. The unique material, developed over 15 years, is more than twice as warm as goose down, yet completely waterproof and windproof. The bag is made from multiple layers of heat reflective and waterproof polymer sheeting, which are interspersed with elastic filaments. This gives the bag a kind of corrugated loft (1cm to 2cm of dead air), with the elastication hugging the body so as to reduce convection to a minimum and aid heat reflection. The inside of the bag is perforated to reduce condensation, but I think any user would probably be fully kitted up inside (although some mountain marathon runners sleep inside the bags in just their thermals at +5°). One problem with the bags is that they are noisy and so I'd recommend earplugs if you know you're going to spent the night in one.

Once the bag has been used it requires a stuff sack to compress it down again (compresses down to the size of a small sleeping bag) and can be reused as much as you want. I've seen testimony from several users who've been forced to spend the night out through injury or bad timing, both in the UK and the Alps (winter and summer), all of who were surprised how comfortable the bag was, along with Alpinists who are now using the bags as a lightweight alternative to a bivvy/sleeping bag combo.

The Blizzard also comes in a two/three person tube bag (530g/£27), which I think would make a great mountain marathon/emergency bag and they even make a jacket out of the stuff, which although looking a bit 'Doctor Who' could be a real winner for guides and instructors.

SLEEPING BAG COVERS

A sleeping bag cover is a bivvy bag that lacks the ability to totally seal oneself inside it. The bag is usually mummy-shaped (not boxy like a bivvy bag) designed to match up with the sleeping bag within it. They are primarily intended as lightweight weather resistant shells (not stormproof) for sleeping in damp environments where you're not expecting direct rain/snow on to your head, places like wet tents, snow holes, huts and caves. If you do get caught out in the direct rain it's usually a case of sealing it up as tight as possible and accepting some water ingress or finding some shelter for the opening (like putting your head in your bivvy bag or draping your shell over your head to form a cowl). The upside is that the lack of a cowl etc keeps both the weight and the cost down; the downside is that for some open bivvys the lack of a cowl could be a real problem.

MOUNTAIN HARDWEAR CONDUIT SL BIVVY

Price: £80 Weight: 510g

The conduit is a good compromise between weight, function ability, weatherproofness and cost, featuring a highly water resistant and breathable Conduit upper and totally waterproof urethane floor - with the whole bag being taped. One very interesting feature of this bag is that it features a full length water resistant zipper, which allows it to be zipped into compatible sleeping bags and gives the easiest access of any bag on the market. Of course, the down side is that this is also a potential leak point in rain. The bag also has internal toggles for holding Mountain Hardwear's line of sleeping pads in place (you can modify your closed cell mats to mate with these toggles with a bit of jiggery-pokery.

RAB SURVIVAL ZONE

Price: £55 Weight: 400g

Waterproof, tough, compact, breathable, lightweight and, best of all, cheap. The Survival Zone is one of the best (and often overlooked) products on the market. The coated Pertex (Aquabloc) sheds snow and wet nastiness well and the bag suffers from virtually no condensation. A simple product that works.

WATER RESISTANT FEATHERWEIGHT BIVVY BAGS

This category of bag could be termed as pure subzero products, designed to keep snow out of your pit. By taking away the waterproof element in the design the weight can be reduced and the breathability increased. These bags are water-resistant and will shed light rain but anything heavier will penetrate the bag.

PHD DELTA BIVVY

Price: £90 Weight: 410g

This super light full spec bag is constructed from DriShell, a lightweight water-resistant fabric (the same water resistant fabric used on most top end bags). The bag is designed for subzero use, or in damp conditions (not direct rain) and so is untaped which also saves weight. The bag features a very large cowl (vital for open winter bivvys) and a short side zip to aid entry and exit. I've used one of these bags for years and found it a great winter bag, although it needs careful washing and reproofing to keep its water resistance up to scratch. The weight is high considering the fabric used but this is due to the bag's features (like reflective tape on the hood and its zip), but could be made lower by Pete Hutchinson if required (all PHD is made to order).

BIBLER WINTER BIVVY

Price: £99 Weight: 261g

A truly minimalist bivvy bag, the Winter Bivvy is made from Nextec Epic, a breathable, silicone encapsulated polyester rip stop. This fabric allows the Winter Bivvy to pack to a stupidly small size and the weight speaks for itself. The Epic is very water resistant and although it will see off short showers and light rain it is primarily designed to be snow proof. The bag features a shoulder-to-shoulder zipper, a cowl and is long enough to sit up in. LIGHTWEIGHT WATERPROOF BIVVY BAGS

MACPAC ALPINE COCOON

Price: £130 Weight: 600g

As you'd expect from Macpac this is a full spec bivvy bag, featuring a full and well-shaped cowl, insect mesh cover and side zips (designed for tying in). The upper of the bag is made from waterproof Reflex Nova - which seems very weatherproof - with the bottom being lightweight UV40 (their flysheet fabric). The fit of the bag is slimmer than most designs, helping to keep the weight down but also making it a squeeze when trying to fit four season bags inside it. When you use this bag you can tell whoever designed it had spent a lot of time out in the open.

OTHER BIVVIES

The bags covered above are what I consider to be either unique or stand out products, but the majority of bags bought come from Terra Nova and Outdoor Designs, with prices ranging from £80 (for half non-Gore bags) to £220 for a full spec Gore bag. Of these bags the stand out product is probably the Outdoor Designs Assault (£160 780g), due both to its design and the use of Gore's excellent Exchange fabric.