Youth life jacket requirement for out of stater

Per DMR: Marine Patrol offers these tips for safe boating:
1.* FIRST AND FOREMOST, WEAR YOUR LIFE JACKET!
The number one cause of death on the water is drowning. The majority of persons who drown are not wearing a lifejacket. The DMR strongly recommends that you wear your life jacket. Mississippi law requires that you must have a wearable personal flotation device (PFD) for each person onboard your vessel while it is in use. It also requires that children 12 years and younger wear this PFD while onboard vessels less than 26 feet long while the vessel is in use. The law also requires that a PFD must be worn while operating or riding on a personal watercraft (PWC).
*
Can anyone define "in use"? My 11 yr old son
will be fishing with me. Does this mean he must wear it at all times or when under power?

Thanks

Your 11 year old must have one on as soon as he gets in the boat and cannot take it off until he gets out of the boat

What Dee said

Thanks guys

Common sense says he wears it all the time while in the boat

yep . If you go grabbling be sure to get out before taking life vest off . Always wondered where they think you are most likely to drown . lol

If the boat is under 16 ft long no one can remove their life jacket.