Definitely throw scenarios at them at random times during the course (once they've learnt how to deal with the skill, of course)

During panicked diver on the surface, have some fun with your DM as well. Get them to start panicking as hard as they can, then sit back and watch, don't go in to rescue/manage. It's a good way to demo how quickly a panicked person will run out of steam and become easier to deal with.

During lost diver scenario, have your DM unplug their LPI inflator, simulating an out of air. The rescuer will have to manage the lift using their own inflate.

Chat to your local EMS and see if they would like to get involved, if so, how. I know in the UK the coastguard are often looking for willing members of the public to train on... imagine how quick a rep you'd get if the final scenario of your course involved real communications to a coastguard station, culminating in your lost now found diver being airlifted and medivacced out!