Scuba diving is where a diver goes underwater using a breathing apparatus which independent of a air support system separate from air above water.
I have never been scuba diving before! I have always wanted to go.
Scuba divers sometimes use additional tanks or cylinders for decompresion gas or to use when an emergency occurs.
That's good they shpuld always have a back up plan!
There are closed circut or semi closed rebreather systems which allow people to breath recycling of breathed out gases.
I know we breathe out carbon dioxide which is toxic so thats good that they don't breathe it back in.
cylinder or cylinders may be used for an equivalent dive duration. Rebreathers extend the time spent underwater compared to open circuit for the same gas consumption; they produce fewer bubbles and less noise than open circuit scuba which makes them attractive to covert military divers to avoid detection, scientific divers to avoid disturbing marine animals, and media divers to avoid bubble interference.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface-supplied diving
Scuba diving
Scuba diving is a mode of underwater diving where the diver uses a self-contained underwater breathing apparatus (scuba), which is completely independent of surface supply, to breathe underwater. Scuba divers carry their own source of breathing gas, usually compressed air, allowing them greater independence and freedom of movement than surface-supplied divers, and longer underwater endurance than breath-hold divers. Although the use of compressed air is common, a new mixture called enriched air (Nitrox) has been gaining popularity due to