Scuba diving is a form of underwater diving where a diver uses a self-contained underwater breathing apparatus (scuba) to breathe while underwater. The diver carries a tank of compressed air on their back, which is connected to a regulator that allows them to breathe air from the tank through a mouthpiece.

Scuba diving enables divers to explore underwater environments for extended periods of time and at depths that would not be possible with just a single breath. It allows divers to observe marine life, coral reefs, shipwrecks, and other underwater features up close.

Before diving, scuba divers are typically trained in the use of the equipment, underwater communication, diving safety procedures, and techniques for managing underwater risks such as decompression sickness. Scuba diving can be done for recreation or as a profession, such as in scientific research, underwater photography, or commercial diving.