You're out sailing on the beautiful, vast reaches of the sea. But the tide starts to pick up, a colossal wave violently crashes into your boat. You lose your bearings as the ship flips head over heels You're trapped in your cabin, sinking into the depths of the sea, with little food, drinking water, or supplies. There have only been a handful of people who have been stranded underwater, and lived to tell the tale. On May 26, 2013, Harrison Okene, was trapped in his tugboat after it capsized. It sank over 30 m (100 ft) to the bottom of the ocean. He survived for a breathtaking three days, before he was rescued by a diving team. But it wasn't just luck that helped him defy death. It all came down to physics. You're probably going to need some air, and you'll need to find it quick. On average, most people can hold their breath for about 30 seconds. After that, your chances aren't very good. When you're unable to breathe, carbon dioxide can't leave your body, so it builds up in your bloodstream. It acidifies the blood, and can kill you in just a few minutes. But if you're trapped in an area with rooms, like a boat or a cave, swim up. You might be able to find an air pocket. Any air that's trapped in a room will rise above the water, making an air bubble that you can breathe in. Now that you've found some air, you might be feeling a little chilly from swimming in the cold water. Hypothermia sets in when a person's temperature falls below 35°C (95°F). You'll start to shiver, feel tired and confused,```` lose consciousness, and die within hours. If you didn't pack your pool floaties, try to find anything that you can use to keep yourself above water, like wood debris. Okene found a mattress to keep him afloat. This will help slow down the amount of body heat you lose, and help to prevent hypothermia. You might think that running out of air is the next problem you'll face in an enclosed space. But you'll build up toxic levels of carbon dioxide in your blood before you use up all the oxygen. Splash the water inside your air pocket. That'll increase the surface area of the water so it absorbs more CO2, helping to keep the amount in your blood from reaching toxic levels. Panicking and hyperventilating uses a lot more oxygen. The more oxygen you take in from the air, the faster you'll run out of it. And you'll be replacing it with toxic CO2. Keep calm by thinking of loved ones, your favorite activities, or thinking of a happy place. Unfortunately, if you're stuck in deep waters, you probably won't be able to swim back to land. Your best chance of surviving is to live as long as possible until a rescue team arrives. Once you make it out of the water, the danger doesn't end there. You'll have to enter a decompression chamber to readjust from deep water pressure to normal pressure levels. The decompression process can last for days, depending on how long you spent underwater, and how far down you were. But, now you've made it! You've survived being trapped in one of the deepest dangers you might find yourself in. So the next time you go out on the water, don't go alone. Always make sure someone on land knows when you plan to return. If you do find yourself in a situation like this, they can send a rescue team to find you. Now that you're ready to survive being trapped underwater, you might want to be prepared for the disasters that could cause such a problem in the first place. Stuck on a sinking ship?
