Accident prevention is one of the most important goals of diver education. Our bodies are adapted for life on land, and the physical characteristics of the underwater world present new hazards to our safety.
During Chapter 4 you learned that the absolute pressure experienced by divers is significantly higher than atmospheric pressure on land. This presents special dangers for divers. Our air spaces can be physically damaged by changes in air volume, bubbles can form in our blood and tissues, and our bodies can suffer adverse reactions to pressurized gasses in the air we breathe.
Fortunately, serious accidents are rare, and most divers never suffer from the conditions covered in this chapter. This is due in large part to the training divers receive during their certification courses.