Under 25
You could buy your own portable diving compressor, my dive buddy has one, there not silly expensive . You must get fills from a compressor designed for diving (breathing) as the air is filtered and moisture removed.
The red sea has the best scuba diving in the world because of the sink boats and tanks to build up the reef.
Its not really scuba diving but its considered scuba diving. Also known as the hookah system. its when you have a gas powered motor pumping fresh air to the person or person's diving below, there can be up to four people diving off of one hookah system. the benefit of this system is that there is no decompression time and you can be underwater pretty much all day if someone fills the gas tank on the engine pumping air. but you are kinda tied down to something so i don't think its true scuba diving.
It increases failure points.
Most SCUBA divers dive with compressed air, which is normal atmospheric air compressed into a scuba tank.
Scuba divers require increased air pressures in their air tanks while diving because the pressure on their bodies increases.
Naturally the air we breath has 70% of nitrogen and only 21% of oxygen, this is done is scuba diving as well. Just oxygen is not enough for living, while oxygen is essential one.
Because the air is compressed so that the same amount of air fills much less space meaning more can be put into a SCUBA cylinder. Normally a tank will be pressurised up to around 3000psi/200bar of pressure.
SCUBA tanks are metal (usually steel or aluminum) that are filled with compressed air. This is loosely related to a pneumatic system.
Hide behind those water tanks. The scuba tanks are filled and ready to go.
The amount of helium in a tank depends on how big the tank is (volume), the pressure of the helium and its temperature. It is calculated from the ideal gas equation with allowance for compressibility.
Since I still consider myself a beginner at scuba diving, I would highly recommend obtaining your very own wet suit, flippers, mask, and snorkel before making any larger purchases such as a BCD, regulator, and tanks. I would check your local listings to find a dive shop in your town and they will be able to assist you in scuba lessons and certification.