What is the role of a lifeguard's whistle?

The role of a lifeguard's whistle is primarily to attract attention during emergencies or to communicate important information to patrons. The whistle serves as a loud signal that can be heard over the noise of a crowded swimming area, allowing lifeguards to quickly alert swimmers, staff, or bystanders when immediate action is required, such as during an emergency situation. Additionally, the whistle is used to communicate instructions or to get the attention of individuals who may not be paying attention, ensuring everyone's safety in the aquatic environment. This effective communication tool is crucial in maintaining safety and order in swimming areas. The other options do not represent the key function of the whistle in the lifeguard's responsibilities.