Latest Global Scuba Diving Destination News and information
Posted by: sddiver96 on Mar 18,
Many divers have asked, "What are the reasons why I am forced to wait until clear to fly after a dive." The reason is all down to something called pressure. When we are positioned on the ground, in other words not underwater or up in the air, we have a weight upon us of about one atmosphere. In fact, we are not even aware of it. This is why we go about our daily lives not knowing there is any weight pushing down on us at all, but there is, albeit one atmosphere.
When we dive we descend downwards into water and the deeper we go, the more pressure is upon us. In fact, for every 10 metres (33 feet) we dive, we add another one unit of atmosphere to the weight that is upon us. So, if we dive 30m (99 feet) we would have four atmospheres of pressure upon us.
When the human body has this much pressure weighing down on us it naturally tries to compensate by causing the nitrogen in our bodies to go into a solution in the blood stream, and the plasma becomes saturated. Once you at depths of around 100 feet the plasma becomes super-saturated.
When you go up in a plane or fly (even at low altitude levels) the opposite effect happens. The pressure decreases. When the pressure decreases too quickly it causes the nitrogen in your body to leave its solution and in doing so it begins "bubbling."
This bubbling effect is similar to when you open a can of cola or pop bottle. The CO2 in the bottle is under tight pressure and when you open the lid to expose it to the air, which of course contains much lower pressure, the liquid starts to bubble.
This bubbling effect can happen when a diver comes up too quickly from the sea bed to the surface. This is often known as "the bends."
Many divers, particularly those who dive on coral reef island chains, often dive and then quickly fly on to another close by island. If there is not time taken to acclimatize and level the pressure out, then serious health risks can occur.
To be absolutely safe when diving and flying, you should leave at least 12 hours between a dive and a flight. This will give your body ample time to acclimatize and prepare for the varying pressure it will be placed under.