Biome · the tide sets your clock
Coast / islands
The coast is not so much a separate biome as a layer on top of any other one: behind your back there is forest, taiga, desert or tropics, and that chapter is yours too. The sea adds three things: plenty of food, no drinking water at all, and a clock of its own — the tide.
Если вы оказались на побережье
- Сначала уйдите из зоны воды. Поднимитесь выше свежего мусора, водорослей и следов прибоя; не ставьте лагерь в устье, сухом русле или под обрывом.
- Знайте сигнал цунами. Сильное или долгое землетрясение, внезапный уход моря либо громкий рёв — немедленно на возвышенность или дальше вглубь, не ждите сообщения и не идите смотреть.
- Найдите пресную воду. Морскую воду пить нельзя. Собирайте дождь, используйте известный пресный источник и обеззараживайте; кипячение не удаляет соль.
- Сделайте укрытие от ветра и солнца. Закрепите тент низко, утеплитесь от мокрого песка и приготовьте путь отхода выше при росте воды.
- Берегите раны и еду. Промывайте раны чистой пресной водой и закрывайте. Моллюсков и рыбу употребляйте только свежими и полностью приготовленными; при предупреждении о токсинах не собирайте.
- Вода быстро отступила, земля дрожала, уровень растёт или слышен рёв — бросьте вещи и уходите вверх. Первая волна может быть не самой большой.
Day 1, hours 1–2 — the tide line and fresh water
⏱ 30–60 minutes. The first thing to establish is how far the water comes upFind the highest tide line: the band of weed, foam, debris and driftwood on the beach. Everything below it goes under water twice a day — you cannot sleep there, leave things there or light a fire there. Camp goes above that line with a margin.
Fresh water: streams from the landward side, a lens of fresh water at the foot of the dunes — a hole dug in the sand behind the first dune often gives brackish but usable water (fresh water is lighter than salt and floats on top of it). Rain catchment is the cleanest source of all.
How to make fresh water out of sea water
При исправной перегонке соль остаётся в исходной ёмкости, а пар конденсируется отдельно. Но самодельная система легко загрязняет сборник брызгами, опрокидывается и расходует много топлива. Это резервный способ только при подходящей металлической посуде, устойчивой конструкции и постоянном присмотре.
- Pour sea water into a vessel and put it on the fire. Fill it no more than half full — otherwise spray with salt in it flies into the place the steam is collecting.
- Cover the vessel so that the lid is sloping: a piece of tin, a broad leaf, a flat stone or an upturned bowl will do.
- The steam settles as drops on the underside of the lid and runs down the slope to its lowest edge. Put a second vessel there.
- It helps to cool the lid — put a wet rag or a cold stone on top of it. The colder the lid, the more drops you get.
- Taste the water you get: it should have no salty taste at all. If it is brackish, spray is reaching it — turn the fire down.
Count the cost honestly. Выход зависит от посуды, герметичности и охлаждения, а всё время нужны топливо и присмотр. Поэтому дождь и проверенный пресный источник остаются приоритетом; перегонка — резерв, а не обещанный суточный объём.
Do not "dilute" fresh water with sea water to make it go further. This is a common and dangerous piece of advice: either way more salt comes in than the kidneys will get rid of.
Day 1, the rest — driftwood settles everything
⏱ shelter 2–3 hours · collecting driftwood as you goDriftwood — the main gift of the coast: ready-made dry boards and beams, sometimes rope, netting and plastic containers. It is the only biome where building material and fuel lie there finished and all you have to do is gather them. The shelter goes up with its back to the wind off the sea, behind a dune or a rock.
Cordage: fibre from shore grasses and palm leaves, and often real cord found on the beach.
🌙 Night 1
The shore is colder at night than it seems: there is almost always a wind off the water, and damp air takes heat faster than dry air. A driftwood fire gives plenty of warmth and shows up well from the sea — on the coast that is more often a plus than a minus.
Check the tide before you sleep. The commonest beginner's mistake on a shore is to fall asleep by the water's edge at low tide and wake up in the water. Mark the current level with a stone or a stick and look again an hour later to see whether it is coming in or going out.
Days 2–3 — learning the rhythm of the tide
⏱ A full tidal cycle is about 12 h 25 min, which means two high waters a dayLow tide is your gathering time: the tidal zone comes clear, with shellfish, crabs, seaweed and fish caught in the pools. High tide is the time for fishing from the shore.
The rule of twelfths — how to know how much time you have
The water does not come in evenly: in the first hour after low water it rises about 1/12 of the whole range, in the second 2/12, in the third and fourth 3/12 each, in the fifth 2/12, in the sixth 1/12. The practical conclusion: the middle of the cycle is the fastest. A sandbar you walked across calmly an hour ago floods three times as fast in the third hour. That is exactly how people get cut off on spits and by rocks.
This is a rough estimate, not a timetable: wind, pressure and the shape of the shore shift the level. Always leave a margin, and never go out onto a sandbar without having your way back planned.
🌙 Nights 2–3
A routine appears: in the evening, fresh water for tomorrow, the catch out to dry or into salt, firewood above the tide line (driftwood left below it will be carried off). Salt and damp air destroy everything: metal rusts within days, knots go stiff, clothing does not dry. Keep your tools and your fire as far from the spray as you can.
Week 1 — from gathering to fishing
⏱ The rest of the weekA hook of bone, thorn or wire from the shore; a stone weir trap in the tidal zone — laid out in a half-circle below the high-water level, so the fish stay in it when the tide goes out. It is one of the oldest fishing technologies there is, and it works with nobody watching it.
The stone weir — a trap you build once
The tide brings fish in to the shore, and the ebb takes the water back out. Put a low wall in the way of the retreating water and some of the fish stay in the pool behind it — and all you have to do is come and collect. Weirs like this served generations on the coasts of the Pacific.
- Wait for full low tide and look over the bottom that has come clear: you want a gently sloping area with a natural dip in it, not a steep shore.
- Lay the wall out in a half-circle or a horseshoe, with the horns towards the shore — along the line low water reaches.
- Height — knee high, that is enough. Lay the stones tight, the large ones on the outside facing the waves, and pack the gaps with small ones: that is exactly where fish get out.
- Work only at low tide and keep an eye on the water coming in. Building a weir waist-deep in water is precisely the case where people get cut off from the shore.
- Come at every low tide. Collect what you have caught by hand or in a basket, and leave the small stuff — it is bait for next time.
Check it after every storm: the waves take the wall apart in a single night. The repair takes half an hour, but noticing the breach in good time is what matters, or you will spend a week walking to an empty trap.
🌙 Night, week 1
The shelter holds off the wind, a store of fresh water is made, and the trap works by itself. The evening check: the tide level, whether the stores are safe from gulls and crabs, clothes drying. On an island you add watching the horizon — a ship or an aircraft goes past suddenly and does not stay long.
Weeks 2–4 — salt
⏱ A few days per batchEvaporating sea water in shallow hollows or stone basins in the sun gives you crystals within a few days. The only biome in this guide where the most valuable resource costs no crafting at all — all it takes is patience. Salt means fish preserved for months ahead and the best goods for trade: everybody needs it and it is produced nowhere but on a coast (see "People").
A month and beyond — fish-skin leather
⏱ 1–2 weeks to work a hideWhere there are no large land animals and plenty of fish, leather was made for centuries out of fish skin — in Alaska, in Siberia, in Scandinavia and by the Ainu in Japan, independently of one another. Take the skin off, scrape away the scales and any remaining flesh, tan it for 1–2 weeks in a bark decoction (tannins) or in fermented urine (ammonia tans as well), then work it soft with your hands. The leather comes out thin but unexpectedly strong and almost waterproof — for footwear, bags and clothing.
Sea and shore
A spit, a sandbar or a shelf under a rock that you walked to dry-shod floods in a time you will underestimate — see the rule of twelfths. Always plan a way back and watch the water, not your catch. What to do: Before going out onto a sandbar, plan the way back and the time. Remember: in the middle of the cycle the water comes in three times as fast.
A narrow flow that carries you away from the shore. Do not swim against it — swim along the shore, across the flow, and only turn for land once you are out of it. Trying to paddle straight for the beach exhausts you and drowns you. What to do: Do not swim against it. Swim along the shore, across the flow, and only when you are out of it — for land.
Do not touch the ones washed up on the beach: the stinging cells stay active in a dead jellyfish and in torn-off tentacles. What to do: Do not touch them even when they are washed up on the beach. If you are stung, rinse with sea water, lift the tentacles off with a stick, do not rub and do not pour fresh water on it.
The risk is greatly overrated. Specific things raise it: water at dawn and dusk, murky water, open wounds, shiny objects. Swimming in clear water in the daytime is not in itself a factor. What to do: Do not swim in murky water, at dawn or at dusk, or with an open wound. If one appears, come out calmly, without thrashing, facing it.
People step on them, not the other way round. In shallow water walk shuffling, without lifting your feet — a ray moves away from the vibration, and you will feel an urchin before you put your full weight on it. What to do: In shallow water walk shuffling, not stepping. If you have stood on an urchin, take the spines out and hold the foot in hot water.
Fresh water: запас, дождь, официально безопасный источник и ручьи со стороны суши. Воду из неизвестного источника обеззараживают; кипячение не удаляет соль или химикаты. Яма с плёнкой даёт непредсказуемо мало и не должна входить в аварийный расчёт.
Food is the strong side of this biome. In order of reliability: fish (hook, weir trap), crabs and shrimp in the tidal pools, seaweed (almost all sea algae are edible — a rare case where plant food is safe), birds' eggs on the cliffs in season.
Seaweed — the rare plant exception
Unlike on land, plant food here is relatively safe: there are practically no lethally poisonous sea algae. Take only the ones attached to the rocks and alive, not the rotting weed cast up on the shore. Rinse it and boil it.
There are practically no lethally poisonous sea algae. Take only what is live and attached to the rocks, not the rotting cast-up weed. Rinse it and boil it.
the tide line · looking for fresh water · collecting driftwood
shelter behind a dune · a fire of driftwood · cordage from grasses or found
закрываемая тара · сбор дождя · снасти · безопасная готовка снаружи
salt by evaporation · smoking and salting fish
fish-skin leather · permanent housing of driftwood
Where to put it
- Above the highest tide line — and with a margin: the line of weed and debris marks the ordinary tide, and a storm adds metres. Build twice your own height above it.
- Behind a dune, a rock or a ridge, not out on the open beach: there is almost always a wind off the water.
- Near fresh water: a stream from the landward side, or a place where you can dig behind the first dune.
- Not in a river mouth and not in a narrow bay — a storm drives water into those.
- Not under a cliff: sea cliffs collapse regularly, that is their normal condition.
- Check whether you can be seen from the sea. If you are being looked for, that is a plus and you camp in plain sight. If you are not, the opposite.
- 1 The tide line. The band of weed, foam and debris. Everything below it is under water twice a day. A storm surge comes up metres higher again.
- 2 A stone footing. A row of stones or short piles: wood on wet sand rots fast, and the sand under a house washes out.
- 3 Driftwood cladding. Boards overlapping, bottom upward, like scales: that way the water runs off outside. Pack the gaps with moss, grass, rags, oakum from old rope.
- 4 A low roof with a big overhang. The lower the silhouette, the less wind it catches. Covering: boards, turf, tarpaulin from your finds, a thick layer of seaweed over the battens.
- 5 Ballast. Stones, or netting with stones in it, over the roof, tied down with ropes to stakes. On the coast it is the wind that takes a roof off, not the rain.
- 6 The hearth on the lee side and sheltered: the wind here does not let a fire stand still. Fuel is driftwood, but driftwood from the sea is salty: it gives acrid smoke and leaves a deposit on your cookware. Rinse it in fresh water and dry it.
- ! Test your site in a storm, not in a calm. The shore on a quiet day and the shore in a surge are two different shores. Until you have lived through the first storm, keep your things ready to move.
How to build a driftwood house
- Collect the material in advance and stack it above the tide line: whatever you leave on the beach goes out with the very next tide. Sort it: long beams for the frame, boards for cladding, small stuff for firewood.
- Dry the driftwood out and where you can, rinse whatever is going into the house with fresh water. Salty wood draws moisture out of the air and never dries out completely.
- The footing: a row of stones, or short piles set on stones. On sand you must widen the bearing — a flat stone under every post, or the post will sink into the ground.
- The frame: four corner posts, a tie beam around the top, rafters. Lash everything rather than nailing it: there are no nails, and there is usually rope from the beach.
- Cladding with boards overlapping, bottom upward. Make the windward side solid and doubled.
- The roof — low, sloping away from the wind, with a big overhang. Ballast on top: stones in netting, logs tied down to stakes.
- The floor raised a hand's breadth off the sand: boards on joists, with air passing underneath.
- The hearth of stones on the lee side, with a flue or an opening with a wind cowl over it.
Salt is the great destroyer. Everything iron from your finds has to be greased, or within a week it turns to dust. Ropes go stiff with salt and break — keep them dry and rinse them in fresh water.
If there is a boat or the remains of one — an upturned hull on props is a house already: that is what was done on every northern coast. It is the fastest route from a find to a home.
Fresh water: the thing that decides the site
Smoke, air and the door
Door
The sign that matters more than any forecast: the water has suddenly gone out from the shore, leaving the bottom bare for tens and hundreds of metres. Or the opposite — the sea comes up with no wave at all. Another sign is a strong earthquake you felt on the shore: you have minutes.
What to do: run immediately uphill and inland, not back for your things and not to look. The target is high ground from 30 metres up, or the upper floors of a solidly built building.
There is more than one wave. The later ones are often higher than the first, and the interval runs from a few minutes to an hour. You can come down after several hours, not before.
It is not the wave that kills but the surge — the whole sea rises by metres and comes inland.
Signs: a long low swell with no wind, a drop in pressure (your ears block), an unusually bright sunset, birds moving inland, the water going murky.
What to do: move higher and away from the river mouth, tie everything down or carry it off, pull the boat well up. Sit it out away from the shore, not "having a look at the waves". Watching the waves is exactly what most of the dead were doing.
The most underrated danger: people walk out at low tide onto a spit, a sandbar or a rock, and then there is no way back.
What to do: before any trip out onto a sandbar, plan the way back and the time. Remember the rule of twelfths: in the middle of the cycle the water comes in three times as fast as at the start.
A narrow flow that carries you away from the shore. You can see it as a strip of calmer, murkier water between the waves.
What to do: do not swim against it — nobody has the strength for that. Swim along the shore, across the flow, until you are out of it, and only then for land. If you cannot swim, stay afloat and do not panic: the current carries you out and then weakens.
Sea cliffs are undercut constantly. Do not camp under a cliff or on the edge of one. Signs: a fresh cone of fallen material at the foot, cracks along the edge at the top. What to do: Do not camp under a cliff or on the edge of one.
It comes in within minutes and takes away every landmark, the shoreline included. Do not go out to sea and do not go far. If it catches you, stay where you are and make a noise; you find the shore by the sound of the surf, keeping it on one and the same side of you. What to do: Stay where you are and make a noise. You find the shore by the sound of the surf, keeping it on one and the same side of you.
Besides a cliff collapse, the shore has two traps: voids in the dunes covered over by a crust, and quicksand in river mouths and on silty flats — waterlogged ground that will not hold your weight.
Signs: sand of a different shade and sheen, water coming up around your footprint, an even surface where there are ripples all round it. What to do: walk on the wet packed strip of the surf line, not on the smooth patch. If you start to sink, do not struggle and do not pull your foot out with a jerk: lie back on your back, spreading your weight, and roll out towards firm ground. To pull someone else out, only lie down and use a board or a rope.
- Time — leave straight away, not after packing.
- Distance — every step away from the source cuts the dose.
- Shielding — any mass between you and the source: earth, stone, water, a wall.
Nuclear
An open shore is a bad place during fallout: there is neither mass nor cover. Get off the shore and inland, into the dunes, into a rock niche, into a basement.
- A wind off the sea is usually your friend: it drives clean air in. A wind off the land in that situation is a signal to move along the shore, across it.
- Water: do not collect rainwater for the first days. Holes behind the dune are safer than open pools.
- Food is the special feature of the biome here. Filter-feeding shellfish (mussels, oysters) push tonnes of water through themselves and concentrate everything in it hundreds of times over. After any contamination of the sea, do not eat them for months. The same goes for the liver and innards of large fish — that is where most of it builds up.
- Small fast-growing fish are safer than large old ones: they simply have not had time to accumulate anything.
Chemical
A spill of oil, fuel or chemicals from a ship is the commonest man-made event on a coast. Signs: a film on the water, rainbow streaks, a smell, dead fish and birds along the surf line.
What to do: get off the shore (the vapours lie low over the water and roll in with the surf), do not collect driftwood and do not burn it — burning contaminated wood releases exactly what you then breathe. Do not collect water, do not take shellfish. Wait several tidal cycles and watch whether life has come back to the tidal zone: birds and crabs on the shore are the best indicator.
Biological
A coast is the place where both people and what is left of them get washed up. The main risk is contact, and water.
- Do not eat shellfish and fish found dead on the shore, however hungry you are. The toxin of algal blooms is removed neither by cooking nor by freezing.
- A "red tide" — the water has turned rusty or green, there are many dead fish, and at night the water glows: take no shellfish for weeks.
- Boil all fresh water. Do not take things from wrecked ships or from bodies.
- Isolate anyone who falls ill, separate dishes.
Path A — with bare hands
You know everything humanity knows, but you have nothing except your hands and what grows around you.
The first year
- Camp above the tide line, a driftwood shelter, fire — the first day.
- Gathering at low tide: shellfish, crabs, seaweed — food from the first hours.
- A driftwood house — 1–3 weeks, half the work already done by the sea.
- A stone weir: a trap that works without you.
Three years
- Salt — by evaporation, with no crafting at all. Preservation, and the best goods for trade.
- Hooks, lines, fish traps, nets of plant fibre.
- Fish-skin leather — where there are no large animals.
- A dugout boat or a raft: the sea becomes a road instead of a wall.
The ceiling, and an honest limit
- Achievable: steady food all year round, salt, housing, a boat, trade with other groups.
- Out of reach: sustained high heat — driftwood is enough for cooking but not for metalworking; salt and damp eat all your iron.
- A peculiarity: the only biome where a surplus appears early and there is something to trade it for.
The bottleneck of this biome
Fresh water. The sea is all around and there is nothing to drink. Everything about where you camp is decided by where you get fresh water.
Path B — on what is left
The same place, but within a day's walk there is something people abandoned. That does not cancel self-reliance — it only speeds it up.
What to look for here specifically
- The sea brings things itself: jerricans, buoys, nets, ropes, plastic, boards, crates. Walking the shore after every storm is what your "salvage trip" amounts to.
- Harbours, jetties, boatyards: motors, cable, tools, fuel.
- Wrecked ships and containers are the biggest prize and the most dangerous one.
- Coastal villages and holiday camps: dishes, containers, tarpaulin.
What that unlocks
- Net and line raise your catch several times over — that is the most valuable thing path B gives you on a coast.
- Plastic containers solve the fresh-water problem: rain catchment becomes a system.
- A boat or a motor turn the coast into a junction instead of a dead end.
The trap on this path
Salt destroys your finds faster than you can put them to use: metal rusts within days, ropes go stiff, electronics are dead at once. And the shore is the most travelled place there is: everybody walks along it.
The ceiling by year
| Timescale | With bare hands | On salvage |
|---|---|---|
| Year 1 | A driftwood house, a weir, salt, steady food | The same in days + a net and containers |
| Year 3 | A boat, fish traps, fish skin, stores and trade | A motor or a sail: a radius of tens of kilometres |
| Year 10 | A settlement of 5–15 people — the highest ceiling in the guide | The same, but by then the iron has been eaten by the salt |
Protecting yourself and your family
Children on the coast. Three rules: do not go out onto a sandbar without an adult (the tide cuts you off), do not swim against the current — swim along the shore, and go uphill if the water suddenly goes out from the shore. That last one is about tsunamis, and it has to be known by heart.