Too young to dive?

[Bob3]

10-12 is the industry average. Personally I look at not only the age but the ability to manage the scuba unit.

My kids used 20 cu ft tanks when they were just ankle biter size; Dacor had a small mouthpiece if I recall but it didn't take them too long 'till they were jamming a Cyklon in their mouths.
Most of the time they hand carried the tank by its valve (old J valves were good hand holders) or tucked it under their arm.