I just got home from the beach. Was walking on the beach with my aunt as well as two little cousins. We stumbled upon CPR in progress for an approximately 20 year old female. Giant ring of people around her calling 911. My aunt brings my cousins to the parking lot so they don't have to watch. From what I could gather from the bystanders, she collapsed 3 minutes ago and CPR was started a minute ago. The lifeguard is doing compressions and a lady comes forward from the crowd and tells her that she is a respiratory therapist. She obviously wasn't breathing (very cyanotic + no chest rise) but the respiratory therapist checked for a pulse and was unsure of a presence of one. I tell the respiratory therapist i'm a certified emergency medical responder and ask her if there's anything I can do. Another lifeguard suddenly runs up with an AED and starts yelling at people to back up if they are not trained. The respiratory therapist yells that she has no pulse and for somebody to attach the AED. The other lifeguard is busy shooing people off and I step forward and start opening up the AED, pressed the ON button, plugged the ADULT PADS into it, and started peeling off the stickies. Someone if cutting off her bikini top with the shears from the CPR kit so I can get the pads on her. Just when i'm about to apply the first pad, the Lifeguard screams for me to "get the f*** away from the AED and i'm not trained to use it". The respiratory therapist (who is ventilating with a pocket mask) tells her i'm trained but the lifeguard ignores her. Police car shows up a minute later and a cop starts bagging the victim. Ambulance shows up two minutes after that and the medics take over. They were still doing CPR on her as they loaded her in the ambulance. It was about 6 minutes before a defibrillator was applied. The victim was apparently by herself and had no family/friends there to give a medical history. This was my first time even close to CPR that wasn't done on a dummy. I'm only 14 and I feel really bad about the whole thing. Should I have just not gotten involved? Did I do the right thing? I'm both mad at myself that I wasn't insistent enough and i'm also mad at the lifeguard. The lifeguard looked 16ish and looked pretty young. I was at least two times her size and i'm not sure if she got mad because I looked too young (most people tell me I look 16ish). Anybody's two cents would be well appreciated?