Dehydration and Scuba Diving

Scuba Diving is an activity totally linked to water. The total immersion of the body in the water returns us to the first moment of our life, in the belly of our mother. Diving allows us to evolve in a liquid environment to discover a new world full of mystery. Water is therefore an integral part of this activity both from an external point of view (the environment in which it evolves) but also from an internal point of view. Indeed, many exchanges of liquids occur in our body during the immersion. What are they and what are their consequences?

What are the mechanisms and consequences of immersion for the diver?

During an immersion, the hydrostatic pressure of the water exerted on the body, will direct the blood of the limbs towards the region of the thorax. This displacement of blood causes anatomical upheavals which will result in a triggering of diuresis, that is to say a secretion of urine. During an immersion, urinary output is six times greater than in normal conditions. This phenomenon is accentuated by difficult underwater conditions, especially in cold water. In these conditions Should you pee or not pee in your wetsuit?.

What is dehydration?

Dehydration is a phenomenon that occurs when body losses water: sweating, urine, stool … are more important than the amounts of fluids that are ingested. One of the most common techniques to know if you are dehydrated or not, is to look at the color of your urine. If it is pale, it means good hydration; On the contrary if it is dark in color, it is time to drink because dehydration is near. If you are thirsty, it means that your body is already dehydrated. The crowning point for a diver is to find himself dehydrated while surrounded by billions of liters of water.

What is the importance of hydration in diving?

Blood contributes to nutrient transport and gas exchange. Dehydration causes blood thickening and reduces blood flow. The term “blood thickening” implies the elimination of nitrogen, which increases the risk of developing decompression sickness.

How to hydrate well?

The ideal is to regularly drink a glass of 15 ml water every 15 minutes. If the need arises, this alert mechanism warns us that it is time to hydrate quickly.

• For children the sensation of thirst appears when it has already lost 3% of its water stock
• For adults, the feeling of thirst appears when it has lost 3 to 5% of its water supply
• For people over that 70 years old, the sensation of thirst appears while it has already lost 5 to 7% of its water supply

When do you need to drink?

To be properly hydrated, it is imperative to drink only water. Indeed, coffee, tea, herbal teas or other sodas are to be avoided because their water balance is zero. Alcohol is even worse as it is a powerful diuretic. It leads to a negative water balance, dehydratation will be worst.

How to prevent dehydration?

Il existe plusieurs méthodes pour estomper le risque de déshydratation, avant, pendant et après, une plongée.

• Do not wear your wetsuit to early
• Respect surface interval
• Do not spend to much time under the sun
• Do not drink alcohol
• Adapt your water consumption according to the climatic conditions of the place where you are

With all these tips you should be operational for your next diving trip!