S: Underwater Science
FC: Underwater Science
2: Everything is different underwater. Water changes what your senses hear, see and feel. It's hard to judge distances, and sounds travel faster than in air. Your body floats and you get cold quickly. It's like an alien world and if you want to stay down there for a while, you need to work out how to breathe, sink and stay warm. UNDER PRESSURE In a dive, your body is under pressure with all the weight of the water sitting on top of it. Dicing 10 metres down under the surface pus your body ender twice as much pressure as on here n land. You can really feel the pressure change in your ears, just like when you dive to the bottom of a swimming pool.
3: Did you know? SCUBA stands for 'self-contained underwater breathing apparatus'.
4: BREATHING UNDERWATER You need air to survive, as you don't have gills like a fish, you need to carry it down with you, squashed in an air tank As you breathe from the tank, an important piece of SCUBA equipment called a regulator makes the air you breathe the same pressure as the surrounding water. THE BENDS Nitrogen is the gas to watch out for when diving. You breathe it in with every breath and it makes up around 70 per cent of the air around us. When you dive down deep, more nitrogen than usual dissolves in your blood. If you come to the surface to quickly, the extra nitrogen can turn back into small bubbles in your blood, which might cause blockages in your tiny blood vessels. To reduce the chance of getting the bends you need to come up slowly, letting your blood's nirtogen levels go back to normal.