22 Jan 2014
Imagine being shipwrecked in the middle of the sea. You are the only survivor on a rubber dinghy, with no water on board. But you are getting thirsty; you need to drink something soon. Your eyes gaze upon the deep blue landscape surrounding you. A few gulps wouldn’t hurt, right? It’s just salty water.
That is true. But the salt is exactly the reason why you need to avoid drinking sea water, especially when you are dehydrated. Sea water has an average of 3.1% to 3.8% salt content, depending on the location. If ingested, it removes moisture from your body through the process of osmosis, unless counterbalanced by ingesting fresh water.
Too much water being removed from your body can eventually cause seizures, unconsciousness, mouth ulcers, swelling of the limbs, brain and kidney damage, and ultimately death. There are plenty of survivor stories detailing how their shipwrecked mates turned to salt water to quench their thirst, and eventually succumbed to madness. A famous one would be Woody Eugene James, a survivor on board the USS Indianapolis in 1943, when it was sunk by the Japanese submarine I-58.
There are still ways to obtain drinking water from the sea. The eyes of a fish and the area around the vertebra are rich in water content. These can be consumed for a brief respite. Humidity that collects on your vessel can also be collected for drinking purposes. If the means are available, salt water can be frozen for it to be drinkable. The salt impurities would sink at the bottom, leaving the water on the top safe for consumption.