Which of the following is an indicator that swimming might not be safe?

The presence of warnings about strong currents or water quality issues serves as a significant indicator that swimming might not be safe. These warnings are crucial as they alert swimmers to potentially hazardous conditions that can pose serious risks. Strong currents can quickly overwhelm even experienced swimmers, leading to dangerous situations such as drowning. Similarly, poor water quality can result in health risks due to pollution, harmful bacteria, or toxins, making it unsafe for individuals to enter the water.

Clear water, lifeguards on duty, and other swimmers present may not necessarily indicate unsafe conditions. Clear water might suggest good visibility but does not guarantee safety. Lifeguards are there to monitor and manage safety, but their presence alone does not eliminate all risks. Other swimmers in the area can provide a sense of community, but their presence does not equate to safety if there are underlying dangers, such as strong currents or polluted water. Thus, understanding and heeding warnings about environmental conditions is essential for ensuring safety while swimming.