Dear Paul,
Sorry if I make more than a few people freak out completely, but actually I myself am a T4 paraplegic, which means (as you would know) I only have use of my shoulders and arms -and head, for what it's worth ;-)... So if I take my two boys diving (i.e. just the three of us) there would definitely be a question of "who can save who".
When it comes to diving with my children, of course I'll have to consider my specific condition. Otherwise, to follow up on your comment above, my kids are strong and healthy, and would be physically able to help each other out, but I guess this is where I join other people's reservations about diving for smaller kids : looking at how they deal with other sports, including pretty extreme ones, I strongly feel they can handle their own selves in the water as well as or even better than many adults I've seen paddling around with diving gear on. However, I doubt they have the mental ability to deal with extreme situations such as having to help or rescue a dive buddy.
Regarding this specific point of 'maturity', and although I agree with certain comments found in other threads to the effect that some adults (specially male) can be just as reckless as kids in the face of danger, I would still say that definitely my older son (12) feels much more reliable than the younger one (10). Physically they're on par, but I doubt either of them can be expected to be a good buddy, even to each other.
This being said, I still intend to take them diving, just as I let them ride their bikes on open roads around our neighbourhood, or climb trees... I am surprised at how divers appear to want to 'over-regulate' the sport, in comparison to mountain climbing for example, where nobody needs a certification to go fall off a cliff or freeze to death in a snow cave... I agree to the need for proper instruction and knowledge, but isn't the whole thing getting a bit out of hand -with the help of 'for-profit' instruction groups who benefit from people's frenzy to acquire extra stars ?
Here you go, now I've gone and made myself a few ennemies... but -just to open a new debate- having 'died' once in a motorbike accident, I feel I should be free to choose my own way to die next, as long as I don't put other people's lives in danger (including my kids')...........Philip