Kathy,
I have a small fishing magnet that Judy bought me for my birthday several years ago. I use it to find tools that I have dropped in the pond. They do work. There are a lot of videos on YouTube that do it. If you find guns, which is commonly found in water near roads, 🐝 sure to call the police, most of them have been used and disposed of by criminals.
The bigger they are the better they are at finding things.
Mine is about two inches in diameter and one inch thick. You?re wasting your time with anything smaller. It can?t pick you real heavy objects.
Jim Altmiller