In a situation requiring signaling for help, which whistle command is most appropriate?

In a situation requiring signaling for help, the most appropriate command is a continuous blast on the whistle. This type of signal is universally recognized as a call for immediate assistance. Continuous blasts can effectively capture attention over long distances and through varying environmental noises, which is crucial during emergencies. The persistence of the signal conveys urgency and importance, prompting those nearby to respond promptly.

Short bursts, like one, two, or three blasts, are typically used for different purposes such as indicating a specific action or communicating within a group rather than alerting others that assistance is needed. Consequently, while those signals might have their own uses in communication, they do not effectively ensure that nearby individuals or rescue teams will recognize the need for urgent help as clearly as a continuous blast would.