Diving is outstandingly popular today. And, in fact, it is not that hard as it may seem at first. Of course, there are many different things you need to learn about diving itself and about diving equipment, but there are many diving centers and organizations that will provide you with a brief and straightforward guide. A diving instructor will explain you the basics and you are ready to make your first dive. It is as easy as 1, 2, 3. Usually, several hours is enough for the person, who has never tried diving before. But it is only a first dive. And if you want to continue your diving career then you need to learn more. Diving is not only the beautiful underwater world, but it is also a hard work, which takes a lot of efforts and needs deep knowledge of diving equipment. For underwater breathing divers use special masks and cylinders filled with compressed air or oxygen. To fill these cylinders with oxygen high pressure air compressors are needed. There are many different air compressor designs. And you can find all the air compressor information on the internet. There are web sites dedicated to diving that provide air compressor information. Or you can find a web page on air compressors in general. These sites will probably provide you with the most detailed air compressor information available. But why do you need all this air compressor information if you want to dive? Because to make all the things right you need to have a clear understanding of how all the diving equipment works. Different models of air compressors work in a different way. And to fill gas cylinder for diving you will need a high pressure air compressors (Diving cylinders are typically filled up with pressure from 2700 to 4300 psi which is about from 18.6 to 30.0 MPa). Most of the cheap models of high pressure compressors work very slowly and you will need a lot of time to fill your gas cylinders. So, what can you do about it? You can fill a bigger container, a bigger cylinder, for example, when you are not diving and then use it as a source of high pressured breathing gas. Most divers actually do this. They have a series of bigger cylinders combined in a cascade system on their boat. They fill diving cylinders with those bigger cylinders. If you are going to dive not so deep then a regular air can be used as a breathing gas for filling diving cylinders. But if you want to take a deeper plunge, then it is better to use air with higher oxygen concentration or pure oxygen. That means that you need a source of oxygen. You can buy cylinders already filled with pressured oxygen, just the same as those used in treatment of different lungs diseases with oxygen healing therapy. There are also special stations where you can get your diving gas cylinder filled with oxygen or its mixture with helium (this mixture is used for even bigger depths). There are also other diving gases that can be used for diving, like Neon and Hydrogen. And it is also important to know about unwanted gases the presence of which in breathing gas can be dangerous. These are Argon, Carbon dioxide and Carbone monoxide.