It depends on how your dive shop teaches it. The only PADI requirement for Rescue Diver is AOW certification.
A lot of shops like to make their own "requirements" so they can sell you more courses...."Yeah you need this and that and this and this here."
EFR is actually day 2 of the Rescue Diver course. EFR is an 8-hour course. Rescue diver is a 23-hour course. In fact, when a student signs up for the EFR course at my shop, they sit in on day 2 of the Rescue Diver course. There they participate with the Rescue Diver students doing CPR on the dummy. CPR is technically a requirement of the Rescue course, but that's a part of the rescue course unless your instructor has chopped it up into several pieces to sell you more stuff. If for some weird reason you just cannot comprehend CPR and you can't pass the CPR requirements on day 2 of the Rescue Diver class, you won't be Rescue Diver certified. But EFR or CPR isn't a prerequisite. (unless your shop is soaking you for another fee).
If your are OW certified and your dive shop is selling you something more than a 23-hour course then find a new dive shop. They're doing the "Yessiireee, the Cadillac is only $18,500!" Then you find out later the transmission is another 10 grand and the motor is another 20 grand and the tires are 2 grand. If you want a radio add 5 hundred and if you want seats, that'll be $6,000 more.
We have a dive shop here in town that price baits like that. Supposedly their Advanced Open Water Certification course is "only $230.00" (they don't tell you you have to buy the air you use and you have to rent their gear and you have to buy their PADI manual and you have to pay for the charters to get the dives that qualify you for AOW certification. So at the end of the day your "AOW Certification" actually costs you about $475, not $230.)
From PADI: "
You also need to have Emergency First Response Primary and Secondary Care (CPR and First Aid) training within the past 24 months. You can complete this training during the Rescue Diver course."
Some shady operators want to sell you a CPR course and the EFR course. They'll tell you you need the EFR course before you can take the RD course. CPR and First Aid is integrated into the Rescue Diver course.
If you review the PADI Master Scuba Diver Application, it asks for 4 things: The date you received AOW cert, the date you received Rescue Diver Cert, the dates of your 5 specialties, and verification that you have the 50 required logged dives. It doesn't ask for CPR or First Aid cert because those are assumed if you successfully completed the RD cert; CPR and FA is part of the RD cert. Neither does it ask for OW cert date because you can't do the AOW or RD if you're not OW certified. So it's assumed also if you're AOW certified then you must be OW certified.
PADI words it a little confusing, but that works out to the dive shop's advantage.
"
PREREQUISITES: Prerequisite certification for enrollment is PADI Advanced Open Water Diver or an equivalent rating. Divers must also complete a PADI Emergency First Response Course or equivalent First Aid and CPR Course prior to course completion."
You'll note that is an "or", not an "and"...
Divers must also complete a PADI Emergency First Response Course *or* equivalent First Aid and CPR Course prior to course completion." As I stated, CPR and First Aid is day 2 of the RD course.
