Field skills: knots, fire, shelter, water, signaling

What this page is, and what it is not

Fieldcraft is the skills half of readiness. Our other guides cover what to own; this one covers the handful of things worth knowing how to do with it, because gear you cannot use is just weight you paid for.

Five subjects earn the space — rope, fire, shelter, water, and being found. They are the ones that recur in every account of a bad night outdoors, and they are the ones where an hour of practice in the back yard is worth far more than an hour of reading.

Priorities, in the order that matters

The rough ordering people use — the "rule of threes" — is a memory aid rather than a physical law, but it puts the right things first: roughly three minutes without air, three hours without shelter in hostile weather, three days without water, three weeks without food.

The useful part is what it demotes. Food, which is what people instinctively pack, comes last by an enormous margin on any timescale a stranded or lost person actually faces. Exposure comes first, and it is what kills people on day hikes a couple of miles from a car park.

Knots: six that carry the load

A knot you can tie quickly in the dark beats a better knot you half remember. Learn a small set and use them for everything.

• Bowline — a fixed loop that will not slip and still unties after being loaded hard. The loop for everything: a line around a tree, a rescue loop, a ridgeline anchor.
• Round turn and two half hitches — the everyday tie-off to a post or a tree. The round turn holds the load while your hands finish the knot, which is what makes it workable under tension.
• Taut-line hitch, or its tidier cousin the midshipman's hitch — a loop that slides to tension by hand and grips under load. This is the guy-line knot, and it is how you retension a sagging tarp at two in the morning without untying anything.
• Trucker's hitch — roughly a three-to-one mechanical advantage for pulling a ridgeline or a load tight, then locking it off. The most useful knot on this list and the one worth practicing most.
• Clove hitch — fast, adjustable, and good for starting a lashing or hanging things off a ridgeline. It can slip under some loads, so treat it as a convenience knot, not a life-safety one.
• Figure-eight on a bight — a loop that is easy to check by eye and hard to get wrong, which is why climbers use it. Worth knowing as the loop you reach for when the consequence of failure is large.

Two habits that matter more than the list

Dress the knot. Arrange it so the strands sit flat and parallel before you load it — a badly set knot is a measurably weaker knot, and most of the failures people blame on the wrong knot are really this.

Cordage deserves a line too. Paracord is convenient and stretchy, and its stated strength is for the whole cord rather than the inner strands. Static line holds a ridgeline tighter with less sag. And none of it is climbing rope, which is a different product with a standard behind it and a price to match — do not use one for the other.

Fire: the tinder is where it goes wrong

Fire is three materials and one mistake. The materials are tinder that catches from a spark or a flame, kindling that catches from the tinder, and fuel that burns long enough to matter. The mistake is skipping the middle one and smothering a perfectly good tinder bundle under wood that is still far too big to light.

Gather all three before striking anything, and gather more than looks right — roughly three times as much kindling as you think. Fires almost never fail at ignition. They fail in the gap between a burning tinder bundle and fuel that is still cold.

• Tinder that works wet: fatwood (resin-soaked pine), birch bark, cotton with petroleum jelly worked through it, and commercial cubes. Two of those cost nothing and one lives in a pocket forever.
• In rain, the dry material is inside things — dead standing branches under a canopy, inner bark, and the heart of a split piece. The ground is the last place to look.
• Feather sticks, where you curl shavings but leave them attached to a dry stick, turn a damp forest into usable kindling with nothing but a blade.
• A ferrocerium rod works wet, works cold, and works after a swim, which a lighter does not. A lighter works better than a rod on every other day of the year. Carry both; together they weigh nothing.
• Lay the fire so air can move through it. A teepee lights easily and collapses; a lean-to against a larger log shelters the flame from wind; a log-cabin stack burns long and steady. Matching the lay to the wind matters more than which one you pick.
• Light from the upwind side, low down, and shelter the first flame with your body until the kindling has genuinely caught.

Fire safety, which is the part with consequences

• Check whether fires are permitted at all. Burn bans and fire restrictions are real, enforced, and posted by land managers; in dry season the answer is often no, and a stove is the alternative.
• Clear a wide circle down to mineral soil, and then look up. A fire under overhanging branches or a standing dead tree is how a campfire becomes a headline.
• Peat, duff, and deep needle litter can carry fire underground for days and surface somewhere else entirely. A fire on that kind of ground is not out when the flames are.
• Have water or dirt within reach before you light it, not after.
• Out means cold. Drown it, stir it, drown it again, and hold a hand near the ashes. If it is too warm to touch, it is not out.
• Never burn anything inside a tent, a vehicle, a snow shelter, or any enclosed space. Carbon monoxide from stoves and fires has no smell and has killed people who were doing everything else right. Ventilation is not a substitute for not doing it.

Shelter: the ground takes more heat than the wind

The most common mistake in an improvised shelter is building a beautiful roof and then lying directly on the earth. Conduction into cold ground pulls heat out of a body far faster than cold air does, and no amount of wall fixes it.

The working order is: get out of the wind, get a barrier between you and the sky, and get insulation underneath you. If you only manage one of the three, make it the insulation underneath.

• Ground insulation can be a sleeping pad, dry leaves or conifer boughs piled a good hand-span deep once compressed, an empty pack, or anything else that traps air. Thicker than feels necessary.
• Small is warm. A shelter big enough to stand up in is a shelter you are heating with one body, and failing. Make it barely larger than you are.
• Site selection beats construction. Avoid the bottom of a valley, where cold air pools; avoid drainage lines and dry channels that move water in a storm; and look up for dead limbs before committing to a spot.
• An emergency bivvy or a heavy-duty reflective blanket is the cheapest and lightest item mentioned anywhere on this page. The flimsy foil ones tear the first time you move in them; the reinforced ones are worth the extra ounces.

Water: the short version

Water has its own page, because the numbers are specific and getting them wrong makes you ill. This is the field-sized summary.

• Boiling has the fewest ways to fail. EPA: bring water to a rolling boil for at least one minute, and three minutes above 5,000 feet.
• Chemical treatment is the backup. EPA's dose for one gallon of clear water is eight drops of 6% bleach, or six drops of 8.25%, stirred and left standing 30 minutes with a faint chlorine smell afterwards. Double it if the water is cloudy, colored, or very cold.
• A filter is a sieve. CDC's emergency guidance is an absolute pore size of 1 micron or smaller to remove Cryptosporidium and Giardia — and a filter alone does not handle viruses, which is why CDC's advice is to filter first and then add a chemical disinfectant.
• The gap runs the other way too: CDC states that chlorine and iodine do not kill Cryptosporidium, which a 1-micron filter removes mechanically. Filters and chemicals cover each other's blind spots, so carry both.
• EPA is explicit that boiling and disinfection do not remove heavy metals, salts, or most chemicals. Floodwater, industrial runoff, or a fuel sheen is a bottled-water problem, not a treatment problem.

Signaling: the whole point is to be found

Search is a numbers game played by other people, and everything you do to be larger, brighter, louder, and more regular improves their odds. Nothing in nature is a straight line or a steady rhythm, so anything you make that is either one reads as human from a long way off.

• Three of anything is the distress convention — three whistle blasts, three fires, three flashes. A whistle carries much further than a voice and costs no energy, which matters a great deal when you are exhausted or hurt.
• A signal mirror reflects sunlight far brighter than anything else you can carry, which is what makes it the strongest daytime signal in a small kit. Aim it by holding two fingers up toward the target and walking the bright spot across them.
• Ground-to-air symbols work: a large V means assistance required, a large X means medical assistance required. Make them enormous, in straight lines, out of material that contrasts with the ground.
• A satellite messenger or a registered personal locator beacon is the highest-value single item on this page. It compresses this entire section into one button, and it works where phones do not.
• And before you leave: tell someone where you are going and when you will be back. A search that starts at nine that evening instead of two days later is a difference no skill on this page can make up.

What this page leaves out, and why

Two subjects belong to a survival conversation and are deliberately absent here. We would rather say so plainly than let the gap read as an oversight.

We do not cover which plants you can eat. Plant identification is the one skill in this whole area where being ninety percent right is genuinely dangerous, and a written list is a poor way to learn it. Our trip planning pages carry photo-paired regional plant references built to be looked at rather than read, which is the only format that is honest for this.

We do not cover taking animals — trapping, snaring, or methods of take. That is regulated wildlife law that varies by state, season, species, and land status, and general-audience instruction on it would be irresponsible and, in most places and at most times of year, illegal. If you hunt, you already work from your state's regulations, and those are the correct source.

Food is last on the priority list anyway. Across the timescale of an unplanned night or two outdoors, it is a morale item rather than a survival one, and the space is better spent on the four things above it.

Where this comes from

The structure and the skill selection here follow US Army survival doctrine — FM 21-76 and its successor FM 3-05.70 — which are US government works in the public domain and free to download. The priority ordering, the shelter-siting cautions, and the signaling conventions come from there.

The water figures are quoted from the EPA's emergency disinfection guidance and CDC's guidance on making water safe in an emergency. Our water guide carries the longer version with the exact wording, and it is the page to read before you need it.

Where this page gives a range instead of a number, that is deliberate — field conditions do not produce single answers. Where you think we have a fact wrong, tell us. Being right matters more to us than being finished.