My childhood was spent on a floating logging camp. I learned to fish before I learned to run from bullys. picture a litle kid with a spin caster set that is taller than he is, with a stainless wing spinner triple hook, and a length of sinkers longer than his d***.. life jacket and all, that's me.
Fishing is a personal thing with me. And, frankly, when you need one of these things you need to fish more. Fish are very testy. Because there is always a larger hungrier fish around, they hit hooks because sometimes it's better to be eaten by god than it is to risk being maimed to death by the devil.
Anyway, if you collect these things, hoorah for the system! There are plenty of ways to figure out if your pole moves. The one I designed has a little string that pulls a stack of cans over. But when you are considering electronic devices and water sports you had better be thinking real clear. My first electronic device shocked the s*** out of me and it was powered by a 3v button cell.. did you know that a 3v button cell can find its way up your arm, under your chin and into your fillings before you bite your tongue, jerk your neck and go limp hoping it will stop? well it can! magnets are really great in that they generally don't shock you badly when you use them near or around water.
You people. You go fishing for say... trout or salmon. You have no idea how much life there is in the water. When you grow up on the ocean, you will never(except maybe once) catch the fish you are trying to catch. And between you and me, I have only been on one fishing trip where the fish the guy caught was the one he was trying to.
Now about the sensor.... alarms scare the big fish away.... you are going to have to be alot quieter.