Why should survivors avoid drinking seawater?

Survivors should avoid drinking seawater primarily because it can lead to dehydration and worsen their physiological condition. Seawater contains high concentrations of salt, which when consumed does not hydrate the body but rather has the opposite effect. The excess salt increases the salinity in the blood, prompting the kidneys to work harder to eliminate the excess salt, which results in a loss of fluids and leads to dehydration.

The body's natural response to high salt intake requires drinking more fresh water to dilute the salt in the bloodstream. However, in survival situations, fresh water is typically unavailable, and drinking seawater would deplete the body’s water reserves rather than replenish them. This can severely impair survival chances by increasing thirst and leading to further dehydration. Consequently, avoiding seawater is a crucial survival tactic to maintain hydration and overall health in emergency situations at sea.