Basic scubadiver your on first base and please continue diving , get better with your gear and bouyance control especially in cold water climates. Second base your becoming an advance diver . My own opinion is one should have about 100 dives before taking a bunch of classes of advance types . Having 100 dives you can hoover horizonal like nobodies business or stand vertical looking at critters or taking a bug or two . Third base is where we are at folks , decompression , mixed gas ,cave and beyond . Please have at least 200 plus more of dives in this field of diving . I was flabbergasted when at the DEMA Show talking to a FBI diver that in thirty days from a non diver became a master ice , cave , rescue and 100 other specialty types with what experience very little to none . Home base is what we are talking about which is rebreather diving and much here to be considered . They may be teaching open water one class with a rebreather now , don't no but do care and happy to be the waterboy for this team of all us scubadivers here on scubaboard . Be good , be kind Rumdumb