Bests & Worsts Reviews from Amazon

I spent a week working out which pool alarm to buy. They are in a category of product where there is a very wide spread of success or failure. I usually add up the 1* and 2* reviews and see what the overall percentage is. I don't usually order anything where more than 10% hate it. This sits at 34% and shouldv'e warned me off. It comes in a nice printed box. The instructions are clearly written by an Engineer as they are overly long and wordy (I know because I'm an Engineer and it's how I would write them). Installation is easy. Just find a spot along the long edge of the pool, mark up the position for a hole and drill it. They don't give a template or include a drill bit which for $200 is pretty shocking. The thing is turned on and off with a little "key". It's basically just a magnet in a rubber case. You only get one and it doesn't secure to the unit. Again, poor for $200. There is an extension sounder that looks like a 4th grade electronics project. It's the cheapest piece of crap I've ever seen. To use the unit, you put it in the water, wait for the waves to subside, and then turn it on with the key by touching a pad for several seconds. There's a dim green LED that flashes to tell you it's working. Our first test worked and the thing went off, as did the extension box in the house, about 30 feet away. It then took me about 5 mins to disarm the thing with the key. It's deafening so you end up shoving your finger in the hole of the sounder, while someone unplugs the house unit. Just when you think its disarmed it goes off again, and again, and again, ad infinitum. Eventually you think it's OK. You walk away, a light breeze comes over, and it's off again. After trying this over a couple of hours I gave up and sent it back. There is no adjustable sensitivty on the unit. None. There is no control app to turn the thing on and off. I'm an Electronics Engineer. I've been desiging products for 30 years. I had a quick look at the parts in this thing. It's essentially a float valve with an actuator that gives a value proportional to its position in the water. Some very basic electronics samples this, looks for an average and fires if the thing is triggered by a large value being sampled outside of the average. The magnet key is almost certainly a reed switch. The entire BOM cost of the thing can't be more than $20, and most of that is the cardboard box! The unit could be vastly improved with some intelligence from a cheap microcontroller and an app on your phone to manage it, which is presumably how lifebuoy etc work. This is like something from the stone age.