A bothy bag labelled for four people is not twice the size of one labelled for two.
For most walking groups in Eryri the Summit Bothy Bag 4 Plus Person is the size to buy. It has the most headroom of anything on this page, at a published 1.20 m.
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| Your day out | What to carry |
|---|---|
| Two people, and the smallest thing that works | Lifesystems Ultralight Survival Shelter 2 |
| Two people who want to sit up | Summit Bothy Bag 2 Person |
| Four people, the common walking-group case | Summit Bothy Bag 4 Plus Person |
| Six to eight people, a leader or club group | Summit Bothy Bag 6-8 Person |
Lifesystems Ultralight Survival Shelter 2
Two people, and the smallest thing that works
Lifesystems Ultralight Survival Shelter 2 220 g, packs to 140 x 75 x 75 mm1400 x 900 x 450 mm up, 20D siliconised nylon, 3000 mm hydrostatic head Read the full specification on Amazon Best where the shelter is insurance you hope never to open.
At 220 g it disappears into a day sack, which is the argument for a pair moving fast on a long day.
The catch is height. At 450 mm it is knee high with two people under it.
That is a low canopy you get under and stay low inside. It is the wrong shape for sitting out an hour of weather and eating something.
Summit Bothy Bag 2 Person
Two people who want to sit up
Summit Bothy Bag 2 Person 1.20 x 0.65 x 1.10 m up, packs to 11.5 cm diam by 18 cmWindow, two 30 cm vents, pole loops, lifetime guarantee Read the full specification on AmazonBest for a pair who want a shelter they can actually use for a stop.
The 1.10 m height is what you pay the extra 144 g for. At 364 gm, it lets two people sit upright rather than crouch.
It also has a window, so you can see the weather without opening the shelter and losing the warmth.
Summit adds one caution on its own page. For extreme arctic use and high windchill it points buyers at its Supalite instead, which has no window.
Summit Bothy Bag 4 Plus Person
Four people
Summit Bothy Bag 4 Plus Person 1.25 x 1.10 x 1.20 m up, packs to 12 cm diam by 19 cmMost headroom on this page, window, two 30 cm vents, pole loops Read the full specification on AmazonBest for the common case: a walking group of three or four on a Welsh hill.
Compare the width with the two person bag: 1.10 m against 0.65 m. That is where the extra capacity has gone, and it is the number that matters when four people sit down.
It has a window, a draw cord round the base and a lifetime guarantee with free repairs.
Summit’s page and the Amazon listing give its weight three ways, from 0.380 kg to 495 grams. Plan on the highest.
Summit Bothy Bag 6-8 Person
Six to eight people
Summit Bothy Bag 6-8 Person 1.75 x 1.30 x 1.15 m up, packs to 13.5 cm diam by 21 cmRPtex PU 4000 HS, window, two 30 cm vents, pole loops Read the full specification on AmazonBest for a leader, a club group, or anyone responsible for more than their own party.
This is the first size where the length grows rather than the width. It goes from 1.25 m to 1.75 m, which lets a second row of people sit down.
At 720 gm it is no longer a thing you forget about. For one walker carrying it for a group of eight, that is the trade.
Where the labels stop agreeing
A person count is a name, not a measurement.
Slide it sideways for the rest →
| Ultralight 2 | Summit 2 | Summit 4 Plus | Summit 6-8 | |
|---|---|---|---|---|
| Stated for, people | 2 | 2 | 4 | 6 to 8 |
| Length, m | 1.40 | 1.20 | 1.25 | 1.75 |
| Width, m | 0.90 | 0.65 | 1.10 | 1.30 |
| Height, m | 0.45 | 1.10 | 1.20 | 1.15 |
Lifesystems Ultralight 2 and the Summit Bothy Bags, on their makers' stated sizes.
Two shelters on that table are both sold as two person, and they share no dimension.
One is 0.90 m wide and knee high. The other is 0.65 m wide and stands over a metre.
Walking alone, and the days you can leave it behind
A bothy bag warms the people inside it with their own heat. A four person bag with one person in it is the wrong buy.
A solo walker wants the one person size. Lifesystems sells one, and says it fits one person with a daysack. It weighs 265 g.
Lifesystems Survival Shelter 1 265 g, packs to 170 x 100 x 100 mm5000 mm hydrostatic head, window, air vent, taped seams Read the full specification on Amazon
The other solo option is a bivi bag, which is a different thing rather than a smaller version of the same idea.
- Bothy bag: you sit under it, upright, with the fabric pulled down over you and your rucksack. It is for waiting out an hour of weather.
- Bivi bag: you lie down inside it, and it is a waterproof outer skin for you or your sleeping bag. It is for spending a night out.
The Lifesystems Venture Solo Bivi is what that shape looks like.
The British Mountaineering Council lists an emergency shelter in what to carry for winter hill walking, beside spare gloves, a hat and a head torch. It names a bivi and a bothy bag side by side as the two answers.
Season matters more than the summit does. A shelter earns its weight on a short winter day far more than on a long June one.
If your walking is the Llanberis Path in August, in a pair, with an hour of daylight spare, you can honestly leave it at home.
How to size one for your own group
The width tells you whether your group fits.
Four adults in waterproofs, with rucksacks pulled in beside them, are sitting shoulder to shoulder. On the Summit 4 Plus they have 1.10 m of it.
Count the people who will actually be with you, then buy the size above it if the walk is a winter one. Bulky layers take room that a summer figure does not allow for.
Height decides comfort rather than fit. Under 0.50 m you are lying low; over 1.10 m you are sitting up.
Last, think about who carries it. A shelter in the boot of the car has never helped anybody.
Which size to put in the sack
For three or four walkers, the Summit Bothy Bag 4 Plus Person is the one to own.
For a pair who want to sit out weather rather than just survive it, buy the Summit Bothy Bag 2 Person.
For a pair counting every gram, the Lifesystems Ultralight Survival Shelter 2 asks you to accept a 450 mm ceiling.
For anyone walking at the front of a group, the Summit Bothy Bag 6-8 Person covers the party you did not plan for.
A shelter turns a bad afternoon into a wait. The reasons a day goes wrong in these hills are worth reading first, in why walkers need rescuing in Snowdonia.
