In the unfortunate event that you find yourself at high sea without any food or water, and it hasn’t rained in a while, would you rather drink sea water or die of thirst? Research shows that you can take one spoon of salty water every 20 minutes, drinking it in small doses so the saliva in your mouth can reduce its salinity.
Seawater makes up about 97.3 percent of Earth’s water, which means that only 2.7 percent is fresh water. If you were to consume a few gulps of ocean water, you would end up urinating more water than you actually drank in order to get rid of the extra salt in sea water, leaving you thirstier and more dehydrated than before.
Your kidneys filter and separate waste material from blood and store it in the form of urine. However, they can only produce urine from a maximum salt concentration of 2 percent. Seeing as seawater comprises about 3 percent salt, your kidneys would have to draw water from your body tissues to dilute the extra salt, leaving your body more dehydrated, and you feeling thirstier.
Check out the Voluntary Castaway experiment to see how you can survive on seawater. Always best to have clean water from a whole house water purification system.