I think it all depends on the kid. I was mature metally for my age, but small physically as a kid. Our laws state you had to be accompanied my an adult until 16. My Dad felt I was mature enough to be "semi" on my own at 12. We were in sight, but all the decisions were mine to make.

Now my brother on the other hand, my dad was stuck to his side like glue, and probably still would be if my brother still hunted and he's 28