Related Videos

How Long Can You Survive Adrift At Sea?

VO: Ashley Bowman WRITTEN BY: Nathan Sharp
For many of us, it's the ultimate nightmare. The scariest thing imaginable. Being lost at sea is surely one of the worst positions a human being can ever find themselves in. But, there have been cases where people have survived being cast adrift in the ocean. Either by skill, endurance or sheer luck, you can spend days, weeks or even months lost at sea - and live to tell the tale! In this video, we find out how...

You must register to a corporate account to download this video. Please login


How Long Can You Survive Adrift at Sea?

It’s a situation that no one wants to find themselves in. Alone at sea, bobbing with the waves, miles of indistinct and seemingly endless ocean in all directions. You worry as your food and water supply (if you even have one in the first place) slowly dwindles, and your anxiety peaks when the sharks come circling. Unfortunately, it’s often a situation that results in death.

One famous and tragic example is the story of Tom and Eileen Lonergan, a couple from Louisiana who found themselves lost at sea after their scuba diving group accidentally left them behind. They weren’t reported missing until two days later. But, by then it was much too late for the couple, whose equipment washed up on shore but their bodies were never recovered. It’s unclear just how long they had lasted, but it was less than 48 hours – showing just how merciless an open water environment can be.

That said, there are various miracle stories of people enduring extended amounts of time at sea – and living to tell the tale. Which got us thinking: Just how long can a human being possibly survive adrift in the open ocean?

Of course, there are huge numbers of variables involved here, chief among them being whether or not you have shelter and/or a floatation device. Naturally, your chances of survival are much broader on a life raft or lifeboat than they would be if you were only treading water in the open ocean. There are also a ton of potentially life-or-death factors when it comes to individual biology and psychology, including your physical condition, mental health, ability to deal with stress, and problem-solving skills. For this video, we’ll be considering a person of average weight, average physical health, and average intelligence (that’s to say, not a specifically-trained survivalist) and we’ll be putting them through three scenarios – one involving a boat with supplies, one with a more makeshift raft, and one with only themselves and the open water.

But first, the boat. And in this case, we mean a small fishing or personal use boat, not a large-scale oil tanker or fully-fledged yacht. Relatively speaking, getting cast adrift in your own vessel is the ideal situation. Boats are obviously sturdy, designed to withstand the sea, and many boast some form of shelter to protect you from the elements. As long as they’re adequately stocked, they should also have food and water supplies, in kits purposefully packed in case of emergency. There’s also a good chance that you’ll have some sort of fishing gear onboard, so you can try your hand at hooking your meals right out of the water itself. If you can find a way to safely prepare fresh fish, it’d certainly beat the typical unappetising rations or canned goods that usually fill a pre-packed survival kit. Above everything else though, boats are also easier to spot from the air, so your potential rescuers should have a much easier time locating you. If there’s a flare or two on board, even better.

When it comes to surviving in a boat, there really isn’t a set amount of time to work with. It all depends on the number of long-life food and water supplies you have, your ability to ration them, your success with a fishing rod, and the quality of shelter. Hypothetically, you could subsist until your supplies ran out, which could take months, or even years. A fisherman by the name of Jose Salvador Alvarenga survived for thirteen months on his boat – from November 2012 to January 2014. The key to his story was that he caught and ate numerous creatures, including birds, fish, and turtles, and he collected rainwater for hydration. Had he not had his boat, these tasks may have proven even more difficult.

Our second scenario sees you stranded in a small lifeboat, or perhaps even an upturned, floating vessel, or a hand-made raft. Lifeboats are clearly not quite as ideal as fully-intact boats, but they still contain crucial supplies necessary for survival – after all, they are specifically designed only to be used in an emergency. Modern lifeboats are typically equipped with various survival tools, including food packs, water (or desalination packs), fishing kits, and flares, ensuring both a basic level of comfort and a high chance of being rescued. The best rafts are also sturdy and safe, although cheaper options run the risk of punctures, holes, and tears.

The good news is that, if you splurge on a decent, high-grade lifeboat (or if the ship you were traveling on provided high-standard rafts), you could be set for a while. Of course, those pesky variables pop up again – as no ‘lost at sea’ scenario is the same – but if the major concerns are cared for, like food, water and a fishing line, your chances are relatively good.

Again, there are various examples of people surviving adrift at sea this way. In 1983, Tami Ashcraft fashioned a platform and sail from what remained of her original (but wrecked) vessel, before surviving for 41 days on peanut butter. Poon Lim was a Chinese sailor who lasted for 133 days on a mere 8-foot square wooden raft before being rescued, in 1943. He did it by fishing, catching birds, and collecting rainwater. Then there’s Steve Callahan, the author of “Adrift: 76 Days Lost at Sea” who survived for, you guessed it, 76 days on a life raft by again catching fish, killing birds, and collecting rainwater… but also by converting salt water into drinking water with two solar stills.

So, it all sounds fairly positive. But, the bad news is that life rafts are not always reliable. Cheaper or poorly made vessels can puncture, tear, and leak, with an increased likelihood of this happening the longer you’re lost at sea. A puncture isn’t necessarily catastrophic, but you’d need to identify and deal with it quickly – which is something you may not have the strength, awareness or expertise to do. Another crucial downside to lifeboats, and your chances of enduring long periods of time on them, is that many do not contain shelter. This means you’d be at significant risk of heatstroke, hypothermia, and general elemental dangers brought on by rough waters that could capsize your vessel.

As with a full-scale boat, surviving in a life raft is definitely doable, and past feats have proven that you can last for months depending on your survival skills, fishing capabilities, the presence of food and water, and a whole lot of luck. However, should you find yourself floating on a flimsy raft in dicey water, you could be in a lot of trouble very quickly. In general, it’s likely that you could survive, but for a much shorter time.

Finally, our last scenario, where it’s just you and the open water. In short, this is bad. And you are all-but doomed if you aren’t rescued very, very quickly.

First off, life jackets are an absolute essential under these circumstances, because you’ll quickly exhaust yourself treading water. There are some short-term alternatives like floating on your back, but nothing much to offer an effective solution for anything longer than a few more minutes. While it does depend upon your own physical condition (and your ability to swim), without a life jacket you could (and probably will) tire and be dead within a matter of minutes, possibly hours. Arlen Gastineau’s story offers some hope, but is very much an exception to the norm – and hinges entirely upon his having a life jacket. He and two friends survived adrift in the Gulf of Mexico for 18 hours after their boat capsized. Between them they had some important survival know-how, but afterwards Gastineau most credited their jackets for saving their lives.

Even with a life jacket though, there are all manner more issues to deal with if you’re unavoidably in the water itself – not least, hypothermia. Much of the world’s oceans range from cold to freezing, especially away from the coast. So, if you’re jacket’s secure and you’re floating, you should bring your knees up to your chest and grasp them as though in the foetal position. This is called the Heat Escape Lessening Position, or HELP – and should keep your body marginally warmer. However, it’ll only help you for so long. The frightening facts are that water temperatures of around 50 degrees Fahrenheit can kill you in an hour; freezing waters can kill you in just fifteen minutes.

As in most survival situations, you should try to remain calm. But, this next danger is arguably the most terrifying of all; sharks. These marine predators often don’t seek to attack and kill us – humans are hardly in their daily diet, after all. But, if you’re treading water in shark-infested seas, your flailing legs are easily mistaken for a meal. And if you are cast adrift with a shark in tow, then your chances are as good as zero.

However, beyond even sharks, the biggest obstacle you’ll have to face is undoubtedly dehydration. In our first two scenarios, on a boat or life raft, survival largely hinged on the availability of food and water, or the possibility of procuring it. In open water with only whatever’s on your person, you’d have neither. Yes, humans have often survived for surprisingly long periods without food, but without water you’d perish within just a couple of days. And that’s before factoring in the untold stress on your body.

Aside from Gastineau, there are very few cases of people who have survived completely adrift without the aid of supplies. In recent news, Kay Longstaff managed ten hours in the Adriatic Sea after going overboard during a cruise. She reportedly sang to keep her spirits up but was physically exhausted once rescued. Her rescuers even admitted their surprise at finding her alive, after such a stretch of time and overnight. Which reveals all you really need to know – even pro sailors were starting to lose hope after just ten hours.

Clearly, there are many variables that contribute to a ‘survival at sea’ story. And there are lots of things that could go wrong. But, the feat isn’t impossible. Should you find yourself on a life raft or preferably a boat, you could hypothetically last for months, or even a year. It all depends on the supplies you have, your own resourcefulness, and an incredible amount of luck. But, when it comes to floating without a vessel in the open ocean, it’d be considered a miracle if you survived for more than a day. There are simply too many obstacles to overcome.

Sign in to access this feature

Related Blogs