Scuba is a recreational activity that allows people to explore the beauty that lives below the surface of the world’s oceans. People also use scuba for commercial, scientific and military purposes. While scuba is not without risk, it is one of the safest sports around when a diver follows the rules and guidelines that they are taught during training.

The most important rule that every entry-level scuba student is taught is to never hold their breath underwater. This is because breathing continuously will prevent serious injury or death from pulmonary baro-traumas. According to Boyle’s law, the air in a diver’s lungs expands during ascent and contracts during descent. This can cause a rupture of the alveoli that make up the walls of the lungs, which leads to arterial gas embolism and can be fatal. Holding your breath will only increase this damage because air cannot escape the lungs to replace it.

Always ascend slowly and carefully, following the “rule of thirds” for air-supply management (a third of your supply for the outward journey, a third for the return journey, and a safety reserve). This will significantly decrease your chance of decompression sickness, which is commonly referred to as the bends.

Admire marine life from afar – this not only protects the fragile ocean ecosystems, but it also keeps you safe. Many coral reefs are sharp and dangerous, and many marine creatures are poisonous or will bite if they feel threatened.