I think using a drone could end up in a disaster.
I tried a remote control boat once, it worked but i didn’t catch anything.
I had a idea for a sort of invention I call a “sinking bobber”. It’s a plastic bottle with holes in the top end that would float out with the wind and or current and sink quickly once it gets full of water.
I made a couple prototypes I just need a windy day to try it off a jetty. I think it would work well with those cast-able crab traps or fishing as well.