Survival tips that may save your life at sea, in the snow, in the desert or the jungle

Diving enthusiast John Low made headlines when he was rescued after being adrift at sea for three days. Shabana Begum looks at the science of survival at sea, in snow, in the desert or the depths of the jungle.

Adrift at sea

For some trips - especially for those out at sea - overpacking is necessary.

Arm your fishing boat or sailing vessel with a life raft in case it sinks or is wrecked. A full-gear life raft should come with at least water, food rations, a torchlight, a whistle, a radar reflector, and a knife or a small fishing kit.

A radar reflector is a lightweight metallic object that reflects radar to all directions so that a passing vessel can detect the float.

The life raft should also be covered to shield the survivor from the relentless heat that can cause painful sunburns.

Science tells us that after the initial waves of panic come over a stranded person, evolutionary survival instincts will kick in.

A 2007 study showed that through natural selection, human beings have become hardwired to pay attention to danger. A biological trigger will help people decide if they stay to fight or flee. Humans have their ancestors to thank for that.

In 1982, sailor Steven Callahan drifted across the Atlantic Ocean for 76 days after his boat sank.

He used a portable solar still to collect drinkable water by evaporating saltwater in a dome-shaped container. The water droplets slid into a tiny trough attached to the water-maker.

Mr Callahan's solar still made about 600ml of water each day. The American inventor and naval architect also collected rainwater for drinking and poured seawater over himself to cool down.

Food was another priority.

He ate the algae and barnacles that crusted his raft after a few weeks. He also caught fish with a spear and ate them live, the fish liver providing vitamins that his body begged for.

Although some fish were food, others were foes. A shark gnawed on his ballast tank while a fish he was trying to spear got the last word by ripping a gash in his raft.

Mr Callahan had to use whatever he had to patch the hole, which took him 10 days.

Dehydration, exhaustion and sun exposure can lead to delirium and hallucinations. To keep himself from having a mental breakdown, the 30-year-old found comfort in routine. He had pencil and paper, and he jotted down his thoughts each day to keep sane.

On day 76, he was rescued by fishermen near the Caribbean islands, miles away from where he set off from the Canary Islands. Mr Callahan wrote a book about his experience which became a bestseller.


Lost in the jungle

In 2015, a 76-year-old hiker became lost in the rainforest near Upper Peirce Reservoir and was found only 45 hours later.

Wanting to explore the Eco-Link@BKE ecological bridge one afternoon, Mr Ng Kang Leng took a detour and ended up in a thick forested area that he could not get out of. As his decision to hike was made on the spur of the moment, he did not have any food or water. Luckily, he had a mobile phone, which he used to call the police.

To avoid getting lost while hiking, explorers should not stray from trails and pathways.

For the next two days, he slept in the wild, drank water left inside discarded plastic bottles and ate plants such as young fern fronds.

He tripped over roots, was pricked by thorns and got entangled in vines. He slept on the ground on the first night and moved nearer to the water on the second night.

After a two-day search, officers found Mr Ng sitting near the water body, about 4km from the PUB Chestnut Avenue Waterworks near Bukit Panjang.

In February last year, two young Singaporean hikers were lost deep in the dense Gunung Pulai rainforest in Johor Baru. They ventured deeper into the mountain in search of a way out, only to find themselves in an area off-limits to climbers, where crocodiles and snakehead fish populated the waters. Ms Clarice Lum, 27, was bitten by a leech and started hallucinating at some point. The hikers were found four days later.

According to the National Parks Board (NParks), if you encounter a wild boar in the forest, keep a safe distance, especially when piglets are with it, as it may be more dangerous while defending its young. Stay calm and do not provoke the animal.

Always carry a compass on hikes to find your bearings as your smartphone may run out of power. Call the police or NParks hotline immediately if you are lost. Do not try to swim across rivers to find your way back as it could be dangerous.


Stuck in a car in snow

During a winter storm, the US Federal Emergency Management Agency recommends everyone to stay indoors and avoid driving.

But if you are caught out and find your car stuck deep in snow with no building in sight, you may be forced to stay in the car for warmth and shelter until help arrives.

Do frequent checks on the car's exhaust pipe to make sure it is not blocked by snow. If it is blocked, carbon monoxide will build up in the car. Tie a coloured cloth to the car radio antenna for rescuers to spot you in the blanket of white.

Turn the vehicle off to conserve energy and turn it back on for 10 minutes every hour to warm up. If you can, do some arm and leg exercises to maintain blood circulation in your body and keep warm.

It is not advisable to eat snow directly because it will lower your core body temperature, increasing your risk of getting hypothermia.

When winter arrives, every car should have an emergency kit containing food, water, extra winter clothes, blankets, a metal container, a lighter, a torchlight and gloves. The metal container and lighter can be used to melt snow to make water.

It is not advisable to eat snow directly because it will lower your core body temperature, increasing your risk of getting hypothermia.

Stay bundled up and watch out for signs of frostbite, such as the loss of feeling around the face, fingers and toes, including hard or waxy skin.

In 2011, an Arizona State University student was trapped in her car under 1m of snow in a secluded mountain range.

For nine days, she survived on two chocolate bars and melted snow by placing a bottle atop the roof of her car.


Stranded in the desert

Last year, New Zealander Claire Nelson suffered a serious fall from a boulder in a desert in Southern California which shattered her pelvis. Ms Nelson, 35, lay on the ground for four days, in the Joshua Tree National Park. She used a stick and a plastic bag to shield herself from the sun's rays.

When her water ran out on day two, she drank her own urine to survive. Healthcare professionals say it is not advisable to drink urine because the waste is expelled from the body for a reason.

Urine usually contains 95 per cent water and 5 per cent waste including nitrogen, potassium, sodium and urea.

By drinking urine over several days, the waste products will return to the kidneys in higher concentrations, and the kidneys will have to work harder to expel the waste. The strain on the organs may cause total kidney failure.

But the dangers of urine intake did not stop Ms Nelson or famed survivor Aron Ralston - who was stuck in a Utah canyon for 127 hours in 2003 when his arm was wedged between a boulder and a canyon wall - to drink their liquid waste when the thirst was unbearable.

Ms Nelson was eventually rescued by a helicopter and Mr Ralston had to amputate his rotting arm in the Utah canyon to set himself free.

If you find yourself stranded in the desert, and are able to move, go to areas with signs of life such as cacti, birds and insects, which could mean that there is a nearby water source.

You can break a cactus to suck water from the plant, but the water contains acids and other chemicals that can be harmful to the body.

As the desert loses heat quickly through radiation at night, it can get cold. Carrying a match while trekking or knowing how to make fire the primitive way using wood will keep you warm in the desert night.

A version of this article appeared in the print edition of The Straits Times on June 22, 2019, with the headline 'Survival tips that may save your life'. Print Edition | Subscribe