The MG International Swim Alert Pool Alarm
One of the best pool alarms made, the Maytronics International Swim Alert Pool Alarm is highly sensitive and must be mounted correctly to eliminate false alarms. It mounts on the deck and the alarm can be heard up to 100 feet away. The immersion probe must be kept at about 8.5 inches beneath the surface of the water or you may end up with consistent false alarms. That said, when it is set up correctly, it is one of the most sensitive and reliable alarms on the list. It will sound an alarm when some object as little as 18 pounds enters the water, which makes it good for animal protection too.