Final answer:
Children under 10 years old must wear a lifejacket at all times to ensure their safety around water and prevent drowning, with exceptions in certain supervised environments.
Step-by-step explanation:
According to the information provided, children under 10 years old must wear a lifejacket at all times to ensure their safety around water and prevent drowning.
However, there may be exceptions to this rule. For example, if a child is in a safe and supervised environment where there is no risk of drowning, such as a swimming pool with a lifeguard present, they may not need to wear a lifejacket.
It is important to always prioritize the safety of young children around water and take appropriate measures to prevent accidents.