Surviving Thirst at Sea

The Risk of Drinking Saltwater

• Saltwater Danger:
  • Saltwater is about four times saltier than blood.
  • Drinking it causes water to flow out of body cells, leading to dehydration.
  • Results in salt poisoning; cells lose water, tissues rupture, and fluids accumulate in organs.

Desalination Methods

Historical Methods

• Aristotle's Concepts:
  • Thermal Desalination: Heat seawater to produce vaporized freshwater.
  • Reverse Osmosis: Pressure-based filtration documented with a sealed wax jar.

Modern Developments

• Thermal Desalination:

  • High energy use from fossil fuels.
  • Produces harmful brine waste.

• Reverse Osmosis:

  • Uses synthetic membranes to filter salt.
  • More energy-efficient, smaller brine footprint.
  • 17,000 plants served over 300 million people by 2020.

Current Challenges and Innovations

• Addressing Issues:

  • Energy, waste management, cost-efficiency, and sustainability.
  • Focus on renewable energy to power large-scale desalination.

• Wastewater as a Resource:

  • Less energy needed to filter contaminants than desalinate seawater.
  • Still provides pure, safe drinking water.

Survival Tips for Being Stranded

Avoid These Actions

• Urine Consumption: Not advisable; leads to kidney damage due to accumulating waste.
• Eating Protein: Increases dehydration as the body lacks water for digestion.

Survival Strategies

• Collecting Water:

  • Use water-wicking materials to gather rain and dew.

• Low-Tech Desalination:

  • Sunbake seawater in containers to collect condensation.

• Alternative Hydration Sources:

  • Bird and turtle blood, fish spinal fluid, and eyes may be viable in dire situations.

Desperate situations might call for creative solutions to maintain hydration and survive until rescue.