mini scuba gear

Question
Hey, i was asking questions on google and it led me to this site but the answers werent what i was looking for so i decided to ask you. I want to know whether or not there is such thing as a mini scuba tank. I dont live near any oceans so i mostly swim in my 12ft pool and i thought that it would be cool to have like a mini diving back pack to take with me when i swim with friends just to mess around lol. I thought of making one but i wanted to make sure there wasnt one already i hope you can help me.
Elijah,

Answer
Hi Elijah,

The short answer to your question is "yes", there are small tanks with a breathing regulator attached.  These are designed for trained and certified divers to use as an emergency air source while surfacing from a dive.

Generally, this equipment is only available to divers who can produce evidence of scuba certification but, as I'm sure you know, anything can be obtained over the internet even if the buyer is not qualified to purchase it on the open market.

The reason for this last statement is a cautionary one for you.  From your letter, I assume that you are not scuba certified and have not had the training required to use this equipment safely.  It's easy enough to operate but that's not the problem.  All the "rules" that we learned as kids are out the window when it comes to breathing compressed air while submerged.  For example, holding your breath on scuba while surfacing from the bottom of your pool can easily result in lung expansion injuries which can prove fatal.  For this reason, I strongly advise you not to pursue trying to use scuba in your pool without proper training.  If you're not sure you believe what I'm telling you, try Googling "barotrauma" or "lung overexpansion injury".

You also indicated that you might just make one.  That's not a good idea either.  Breathing air regulators are designed to operate at high pressures (around 3000 psi) so trying to make one will probably not work and could result in severe injury if it fails.  Keep in mind that 3000 psi is 100 times greater than the pressure in an automobile tire so it's nothing to play around with.  The compressed air we use in our scuba tanks is also highly filtered, cleaned and dried and it's not at all like the air that comes out of a regular air compressor.

Elijah, I applaud you for trying to get inventive, but you're playing with fire when you start messing around with compressed air and breathing it underwater.  I know this isn't the answer you wanted to hear but I'm trying to give you enough information to keep you from getting injured or killed.  That's not an exaggeration when we're talking about breathing compressed air underwater.

Sincerely,
Mike Giles