Something just occured to me that I would like you to consider:DCMG once bubbled...
Im not a diver, but have just signed-up my teenage kids for a course at school.
Perhaps the best way for you to enhance the safety of your children as they take up diving... would to take up diving yourself. Even if you could not take the same classes together since their's will be at school... you could go to the local dive shop and take classes there.
Wouldn't that be great! You could dive with your kids, and oversee their safety!!!