Drinking seawater can be extremely harmful to humans. Seawater contains salt and other minerals that are much higher than what can be processed by the human body. When humans drink seawater, their cells take in water and salt, which can cause dehydration instead of hydration. The kidneys are unable to remove the excess salt, leading to dehydration, kidney damage, nausea, and vomiting. Human kidneys can only produce urine thats slightly less salty than saltwater, so in order to remove the extreme amount of sodium taken in by saltwater, we urinate more water than we actually drank, and dehydration sets in. Drinking seawater can also cause other health problems, such as a drop in blood pressure, seizures, and even coma.

In summary, drinking seawater can lead to dehydration, kidney failure, and even death. Seawater contains salt and other minerals that are harmful to the human body, and the kidneys are unable to remove the excess salt, leading to dehydration and other serious health problems. Therefore, it is best to avoid drinking seawater and to drink fresh water instead to stay hydrated in the ocean.