How long can you survive stranded at sea

There has recently been a story (29/11/20) about a man named Stuart Bee who went out for a cruise on his 32-foot boat off the coast of Florida. He departed from Cape Marina in Port Canaveral on November 27 and intended to stay reasonably close to the coast while he sailed around and did some fishing. He informed the coast guard he was going out as this was his regular spot for launching his boat, and set out into the open ocean.

(Stuart Bee climbing onto the Coast guards ship after being found)

On the same day he set out, November 27, for some unknown reason, his boat began to sway in the water until it eventually tipped on its side and completely capsized. Bee managed to swim out and wasn’t hurt in the event, but now found himself sitting on the underside of his boat with no supplies. The coast guard knew him and thought it was strange that he didn’t come back before dark as he never stayed at sea overnight, and notified another coast guard station who set out looking for him the next day. He was eventually found the day after on the 29th and at approximately 11 am was rescued by the coast guard and taken back to safety uninjured.

Stuart Bee was quite lucky because he was only 86 miles off the coast when he was found, and his survival time was a little under two days, but what would have happened if no one had come for him and how long can you survive stranded at sea?

There are three main factors when it comes to surviving at sea, which are supplies, temperature and expose levels.

Temperature

If you’re lucky enough to find yourself dry and in the shade, then you are only in danger from the temperature if you’re in an extreme climate, but if you’re treading water then your time will be quite short. For an adult of average body size and fat content, the following is a rough indicator of how long it will take for you to pass out, which will ultimately mean your death.

Water temperature to estimated survival time

0.3°        45 minutes

0.3–4.4°         30 – 90 minutes

3.3–10°         1 – 3 hours

10–15.6°         1 – 6 hours

Exposure

If you’re in the water then you won’t have time to worry about exposure, but in the event you have a life raft or you’re sitting on the underside of a capsized boat, how long could you last?

If the climate is extremely hot, then you would still be able to last for a very long time if you had ample drinking water, though it would be very uncomfortable. The biggest threat from exposure comes from infection and dehydration if in extreme heat or direct sunlight. Seawater can leave a tiny layer of salt on your skin which can build up over time and dry out your skin to the point of cracking, which in turn can become infected. The amount of time this would take, if it even occurred at all would depend greatly on the wound and how often you keep getting wet combined with the local climate.

Supplies

This one may seem a little obvious, but what happens if your boat capsizes and you end up sitting on the bottom of the hull? In order to get supplies from the inside of your ship, you would have to swim under every time and try to pass things around and balance them on the smooth and sloping side of the boat’s hull.

If you ever find yourself in this situation and have something you can use as a smashing tool or strong knife, then NEVER try to cut your way through the hull to grab things easier, as this will let out all the air that’s trapped inside and keeping it afloat in the first place.

The longest stranding at sea and how he survived

The Longest survival at sea was by a man named José Salvador Alvarenga who managed to stay alive for 438 days stranded in the open ocean where he floated for 6,700 miles before washing back onto land. He became stranded after going out to sea with a fishing partner to try and catch some tuna but was quickly hit by a storm that damaged all their gear and supplies. After being blown way off course, they found themselves stranded and without food, and it didn’t take long until José’s partner died from a combination of thirst and starvation.
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(José Salvador Alvarenga on the day of his rescue after spending 438 days at sea)

The reason that José managed to survive for so long was because the little food he had left combined with what he was able to scavenge from the ocean lasted him for long enough until the mini eco-system was able to form under his boat which provided the opportunity for food.

How long can you survive stranded at sea in a small boat?

The Mini Eco-system

Floating around in ocean water are the spores of various sea plants, much like how pollen floats around the air to travel to other plants. When these spores meet a surface they can attach to, they often do so and begin to grow. Most of the plant spores that reach so close to the surface are certain types of seaweed and small moss-like plants, but they are enough to in turn attract other things.

The plants attract micro-organisms which in turn attract small fish that feed off them. These small fish attract larger fish looking for an easy meal, as well as various birds who try to catch them and also land on the boat for a rest. With the occasional bird landing on your boat combined with a small amount of fish following you around, you would sometimes be able to catch them and get yourself a meal.

There are also fish and various creatures that will follow the shade of the boat around, which adds to the ecosystem and potential food supply. The amount of food you would get from living off nothing other than what you could catch would be barely enough to keep you alive and would require a complete lack of all unnecessary movement during the rest of the day.

What about water?

It takes around three days for someone to die from thirst, and the open ocean is the worst possible place to be because you have to rely entirely on rain. The only chance you would have is to make something to collect as much water as possible when it rains, and then drink as little as possible while rationing it out.

On a raft or boat, there is usually the chance to make some kind of rain catcher out of a sheet of plastic or some kind of material with a large surface area that runs off into a container, but without the things to make a collector or a container to keep the water in, you’d last as long as the rains allowed.