Different types of underwater diving include :
- Sports diving can be done with air cylinders carried by the diver. This is called scuba diving. It can also be done for shorter dives by holding your breath. This is called freediving.
- Scuba diving is done with metal cylinders carried by the diver to hold the breathing air.
- Military diving using air cylinders carried by the diver has existed since World War Two. Military diving using air supplied through a hose from a pump above the water has existed longer.
- Commercial diving is diving to do underwater work. The air for breathing is usually supplied through a hose from a pump above the water.