Passive drowning is when a victim is not moving either face down or up in the bottom or near the surface of the water. These victims are completely limp, motionless, and unconscious. This can happen from various accidents near or in the pool. A few instances that can cause passive drowning are heart attacks, seizures, head injuries, heart-related illnesses, hypothermia, hyperventilation, alcohol, and drug use. Any victims who seem to be passively drowning should be responded to immediately, but it can be difficult to spot them if they are in deep water. Obstructions like sun glare, reflections, water movement, or other swimmers make it difficult to see people at the bottom of pools. These victims can blend in with the lines at the bottom of the pools, appear to be smudges or shadows, or objects like toys. It is important to be aware of all swimmers and keep a count of the swimmers in your head to know who is in the pool.