Scuba diving is all about swimming beneath the surface while breathing gas that the diver carries with them, usually compressed air, through a SCUBA system. This setup typically includes a diving mask, fins, a buoyancy control device (BCD), a regulator, and a tank filled with breathable gas. With this gear, divers can venture into a variety of underwater settings, like oceans, lakes, and rivers, all while ensuring they have a safe and steady supply of air.