Care needs to be taken when ascending to the surface, as this is the most dangerous time during a scuba dive. How to manage both an emergency and normal ascent?
The Bends
Two of the major hazards in diving are the Bends and an air embolism, both directly associated with breathing compressed air at depth and the ascent. The Bends occurs when nitrogen absorbed into the tissues during a dive is released too quickly into the blood stream when the body is de-pressurised.
The casual diver usually says “I don't have to worry. The Bends only occurs on deep dives”. Ascending too fast can cause a minor case of the Bends. Simply running out of air and not relying on a buddy’s air can lead to a mad dash for the surface which can mean the nitrogen doesn’t have enough time to absorb back into the bloodstream.
Air Embolism
The other major hazard of the ascent is an air embolism, which occurs when air expanding in the lungs during the ascent bursts the lungs. This is a direct result of holding the breath on ascent. It can be from panic or again when a diver runs out of air and attempts a free ascent.
A Safe Ascent
So how to make the ascent safer? First off, never get in the situation where a free ascent is needed. Simply, never run out of air. Sounds simple but all divers at some time are guilty of this problem. Reducing this risk should be part of the dive plan.
