@Diptchip Good to know, but there is really almost no condition in which I'd dive air (though it is common for beginner divers who arent certified to use anything but air).. For me ill almost certainly be diving either shallow with nitrox (higher concentration of oxygen than in air), or at depth with trimix (a mix of oxygen, nitrogen, and helium).
That said if you want to get into SCUBA since the entry level that most people stop at is air only it would be a great purchase for you for sure.