The correct answer to this is that:
The Federal Regulation states that for this case “Children 12 years old and under must wear an approved personal floatation device”
For vessels longer than 16 feet, types 1 to 5 of PFD should be aboard the boat.
Type 1: offshore life jackets
Type 2: Near-shore vests
Type 3: Flotation aids
Type 4: Throwable devices
Type 5: Special use devices or Hybrid PFDs