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Accidents at sea -

Each year, up to 25 people go overboard on cruise ships, 2,000 fishermen are lost at sea, and tens of thousands of beachgoers get caught in rip currents. Not to mention tragic accidents like the 2023 foundering of a Greek migrant boat leaving hundreds of people unaccounted for. 

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The sea's vastness -

Not only does the sea cover 70% of the Earth's surface, but it's also so inhospitable that it can feel like another planet. Being adrift robs a person of every basic necessity for survival. So, how long could someone potentially last after getting lost at sea?

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Only seconds if they give in to panic -

A person who falls into the sea without any flotation device, swimming ability, or knowledge of water safety techniques is a great risk of drowning. However, even skilled swimmers can drown if they give in to fear.

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Drowning -

A person who's panicking will thrash, yell, and desperately gulp air until they succumb to the instinctive drowning response, which causes them to lose control and silently slip beneath the water's surface. 

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Sinking deeper -

As a drowning person sinks deeper, they are unable to reliably inhale air, which leads to increased panic. The average person can only hold their breath for about one minute; after that, they will inevitably start inhaling water. Drowning can occur within seconds to minutes as water fills the lungs.

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Just minutes in very cold water -

Even the calmest and strongest swimmer is no match for cold water. Cold water is anything below 70°F (21°C) and the sea's surface temperature ranges from 28 to 95°F (-2 to 35°C). Water robs a person of body heat much faster than air, making it easier to develop hypothermia.

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Cold shock response -

People submerged in cold water also experience the 'cold shock response,' which occurs when the skin cools so fast that the body can't keep up, resulting in gasping, hyperventilation, and heart strain.

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The cold shock response and the Titanic -

Historians report that the Titanic sank in water temperatures of 28°F (-2°C), and cold shock and hypothermia claimed the lives of hundreds. Practically no one drowned, as some of the recovered victims showed no water in their lungs.

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Hours with nothing but basic water survival skills -

Surviving in open water is possible with basic survival techniques, even without a flotation device. If a person can remain relatively calm, float on their back, hold their breath, and tread water, they can keep themselves from drowning until they are hopefully rescued.

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Wearing a life jacket -

Hypothermia can be delayed if you're wearing a life jacket by employing the Heat Escape Lessening Posture, in which the knees are tucked into the chest to trap as much body heat as possible. Resting while floating on your back is helpful in calm conditions, while floating face down offers protection from wind and waves in choppy water.

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Kay Longstaff -

When Kay Longstaff fell off the back of a cruise ship 50 miles (80.5 kilometers) from Croatia, she survived by floating on her back and singing to distract herself from the cold. She drifted for 10 hours until she was rescued. 

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Up to three days in warmer water without any flotation device -

In water 70 °F (21 °C) or warmer, hypothermia is less of a concern, although eventual dehydration, exhaustion, and low blood sugar will impact the ability to remain conscious. The world record for treading water is 85 hours, though the average person can only keep it up for two to three hours at a time.

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A few more days with water and nothing else -

Despite being surrounded by it, the lack of fresh water is one of the biggest threats to survival when stranded at sea. Not only does being submerged in seawater rapidly dehydrate the body, but drinking it is potentially deadly, as the body must use its internal water supply to flush out the excess salt.

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How much water does the human body need? -

The human body requires between 2.7 and 3.7 liters of water per day, and during physical exertion, it can lose between 3 to 4 liters each hour, making hydration at sea a constant battle.

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Three to five days with just foundation -

Being able to rest out of the water reduces the dangers of cold shock, slows the rate of body heat loss, and allows for energy conservation by reducing the need for constant exertion. 

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Desperate times call for desperate measures -

In 2022, a man named Ivan survived 18 hours adrift at sea using a partially deflated toy ball to keep his head above water off the coast of Greece. 

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Dehydration -

Without water, your days are seriously numbered. The average person can go without hydration for three to four days, although this duration may be shorter depending on the amount of sweating.

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Weeks to months with a proper vessel and adequate water -

With a proper vessel like a life raft or a capsized boat, a person has a better chance of survival. A dry surface alleviates the immediate risks of hypothermia and drowning, making it easier to rest. Materials on the vessel can also be turned into useful tools, such as collecting rainwater.

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Tami Oldham Ashcraft -

Tami Oldham Ashcraft became lost at sea after a Category 4 hurricane capsized her boat in October 1983. She survived 41 days adrift at sea, using a single tattered sail, limited rations, and a sextant to navigate her way to Hawaii.

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Starvation -

While the human body can only survive a couple of days without water, it can survive between one and three months without food, though most people stranded at sea don't make it that long.

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If you're educated about marine life, you're likely to survive longer -

Being knowledgeable about marine life can benefit a person lost at sea. Avoiding thrashing and creating unnecessary noise, which can attract sharks, and staying away from creatures like box jellyfish, which can cause fatal reactions, can prolong a person's life. 

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Avoiding shark attacks -

Sharks will circle and bump objects in the water before striking, so knowing how to intercept an attack is essential. Kicking in the eyes and gills is often enough of a deterrent. 

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Steven Callahan -

Steven Callahan spent 76 days adrift in the Atlantic Ocean after his sailboat sank. During his ordeal, he survived by catching fish and drinking rainwater. He also used the sea life around him to attract birds, which provided additional food sources and ultimately led to his rescue by fishermen who spotted him.

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Several months with food, water, and a sturdy vessel -

A sturdy vessel, such as a modern life raft equipped with shelter from the elements and access to food and water, can allow a person adrift to survive for a long time, provided that the vessel stays afloat.

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A year with luck, creativity, and key items -

A person lost at sea must become very efficient at harvesting food and water to survive a full year adrift. Anything and everything that can catch rainwater is rigged to do so, from plastic bags to boots. Mexican fishermen Jesús Vidana, Lucio Rendon, and Salvador Ordonez, who spent nine months adrift, even built a fishing rod out of engine parts.

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Several years with a sustainable setup -

If you have survived a full year lost at sea and aren't in terrible health or on the verge of death, it's possible to complete another year. Fisherman José Salvador Alvarenga spent 438 days adrift when he finally swam ashore. 

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José Salvador Alvarenga -

Alvarenga was marooned in the Pacific Ocean in 2022 after a storm. He harvested rainwater, ate sea turtles, birds, and fish, and managed to keep his boat afloat.

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Technically forever -

With a buoyant ship, reliable sources of food and water, necessary vitamins, and regular exercise, a person could theoretically remain lost at sea indefinitely, particularly if they were near the equator, where food and rainwater are more plentiful.

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It could be over in an instant -

However, a severe storm, rogue wave, or severe medical emergency could mean your life is over pretty quickly, not to mention the toll on your mental health from living in isolation in such a precarious state.

Sources: (Grunge) (BBC) (Stop Drowning Now)

See also: What is dry drowning?

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