Depends on what agency and where you take it, but for here in our PADI facility, Emergency First Responder/CPR is taught the night before the actual Rescue Course by our PADI EFR Instructor.. When I took Rescue, I was already CPR qualified, so I didn’t go to that portion of the class. As for the Rescue portion itself, it was taught over the course of 2 days.. Mornings in the pool and afternoons in the lake.. It is a grueling two days and it is the most fun I’ve ever had in a training course. I needed some serious Tylenol after it was over. As for the lake diving, you have to do it that way. Kinda pointless to do search and recovery drills in awesome viz water. :) We had less than 6 inch visibility in our local lake and it was perfect for S&R drills. And, you have the right attitude about it.. The PADI Rescue class teaches you NOTHING new about diving, per se. But, it will make you a better dive buddy for anyone from that point on. It will also make you better prepared for emergnecy situations. Enjoy it!! It’s a blast!!