Boat trailers are exempt in Tn. from registration. The license requirement in Ms. says any minor under 16 yoa resident or non resident does not need a fishing license. So I would take that 7yo fishing anytime he wants to go and catch 15 crappie PER PERSON including 15 for that 7yo. Nowhere have I read in the regs does it say a specific age for a fisherman be it 5 or 95, if he can fish and hold a pole he is entitled to keep 15 just like everyone else who has posted in this thread. I would rather see him sitting in a boat with his dad catching fish for some father, son time as playing a dadgum video game. and Mississippi excellent video. Keep him fishing any time he wants to.