adam61, RJP spelled out the differences at the start. PADI changed it's rules in that you don't need AOW, only Advent. Diver & CPR as a prerequisite for Rescue Course (PADI also dropped the 20 dive prerequisite years ago). Actually, I don't disagree with either change, as I think everyone should have Rescue as soon as they are ready). So, if you get Advent. Diver instead of AOW some boats may let you dive to 100' and some may not. But if you take Rescue then DM, all boats let you dive anywhere. I would think not offering AOW and saying that the two are "basically the same" is a local thing with your instructor/shop. That's just what is done there.