Leave auto settings alone and teach them to shoot in manual so that they may manipulate the camera instead of the camera manipulating them.
I think all new comers (land or underwater) need a good grasp of the interplay between shutter speed, aperture, and depth of field. They need a good grasp of the concept that there are many shutter speed/aperture settings that will yield the same exposure. Which one is correct for any given shot will be determined by that particular shot, for instance, if you wanted a great depth field, or if you wanted to take advantage of ambient light or just strobe, fast moving subject vs slow. These are but a few of the nuts and bolts that will turn a snapshot into a photograph.
I think all new comers (land or underwater) need a good grasp of the interplay between shutter speed, aperture, and depth of field. They need a good grasp of the concept that there are many shutter speed/aperture settings that will yield the same exposure. Which one is correct for any given shot will be determined by that particular shot, for instance, if you wanted a great depth field, or if you wanted to take advantage of ambient light or just strobe, fast moving subject vs slow. These are but a few of the nuts and bolts that will turn a snapshot into a photograph.