What is a critical sign that a swimmer may be in trouble?

A critical sign that a swimmer may be in trouble is flailing arms and legs. This behavior often indicates that the swimmer is struggling to stay afloat and may be panicking. When a person is in distress in the water, their movements become erratic as they thrash about in an attempt to save themselves. This can be a clear indicator that they are unable to swim effectively and need assistance.

In contrast, loud splashing noises may simply be a sign of someone having fun in the water rather than being in distress. Calm swimming movements usually suggest that a swimmer is confident and in control of their swimming, while moving to the shallow end is typically an action taken by swimmers who feel secure and wish to traverse to a safer area. Therefore, flailing signifies immediate danger and the need for intervention.