I've followed most of the threads, and didn't see anyone else mention the local practice at La Jolla Shores (San Diego)...
The instructor checks in with the lifeguards at the main tower, and the victim (and only the victim) wears a bright orange swimming cap (or hood?).
If the guy yelling for Help is wearing the orange cap, they watch the instructor and class and if all goes well, they know not to respond. If a bystander goes to the lifeguards, they can explain what's going on.
The instructor checks in with the lifeguards at the main tower, and the victim (and only the victim) wears a bright orange swimming cap (or hood?).
If the guy yelling for Help is wearing the orange cap, they watch the instructor and class and if all goes well, they know not to respond. If a bystander goes to the lifeguards, they can explain what's going on.