I agree with the others , the fact that you are considering a tether says he should not be diving. The question in your mind about the tether is your inner voice of common sense, or instinct if you will, telling you there is a risk here you should avoid. Listen to the voice. In addition, do you really think you could hold down your son in a pannic trying to get to the surface swimming as hard as he can, and maybe even inflating his BC? Is diving now worth the risk of his life?htn123:... I think this has more to do with me than with him ...
At his age that is normal and life threating in the SCUBA environment! :11:htn123:...he wants to show that he is better than her in everything. I was just concerned that he might want to show off that he can handle it just to be competitive with his sis....
Now I must also discuss my bias. I don't believe children under 17 or so should be diving at all. At 10, even intelligent children, have not yet developed all of their mental capacities yet. Example, his competivness with his sister. Children of that age also do not have the alacrity of mind to calmly stop and think there way out of a situation and may panic and bolt for the surface. This is a common problem of kids in their teens. You can point to things like smoking and how addictive it is, but they say it wont happen to me but never have a reason as to why not to them but everyone else. In their world, if they do something and do not see an immediate result or consequence, then it is not an issue. Blowing off a safety stop or ascending too fast is such an event.
Bottom line, for some reason, you are thinking of a tether. At some level you know there is an issue or potential for there to be one. Is your sons life worth the risk? He should IMHO wait several more years before diving.