What is a common signal used to alert fellow lifeguards of an emergency?

Raising both arms in the air is a common signal used by lifeguards to alert fellow team members of an emergency situation. This gesture is universally recognized among lifeguards and serves to quickly attract attention and communicate urgency without the need for verbal communication, which may not be heard in a chaotic environment or over the sound of waves. The simplicity and visibility of raising both arms make it an effective method to convey that immediate action is required.

Other options, while they could theoretically signal for attention, do not carry the same level of urgency or clarity in a lifeguard context. For instance, waving a flag is typically used for communicating with beachgoers rather than alerting fellow lifeguards, and clapping loudly might not be effective in a noisy setting where the need for immediate response is critical. Continuously blowing a whistle is often used to signal a warning but may not distinctly indicate that an emergency situation has arisen, making it less effective for signaling a team response.