Here is one of my ideas I got as far as buying supplies for but just never fully realized.
I spent a lot of time thinking about and sketching up this crab trap.
The idea was simple, people have to check the crab pots by pulling up the pots from the ocean floor to see if they had bait and if crabs were in there.
My idea was to have a buoy with a light on top that would alert you when the bait had been disturbed.
When you got to the buoy you would then plug in a video screen up to the top of the buoy and connect to the camera inside the crab pot so you could check to see if it was time to pull it up.
I devised several versions of this idea and thought long and hard how I would design the bait switch and the camera system.
Maybe ill get around to it and build one for myself, but either way feel free to build your own for non commercial purposes of course.
First was the idea of having a camera and a buoy that would blink when the trigger bait holder was disturbed. So I sketched some IR LED lights, a camera and the bait holder, this would be inside the crab trap. The wires would ride along with the buoy rope and go inside the buoy and trigger the blinking crab alert light.
I started thinking about the bait to buoy connection to trip off the blinking light, here I have the whole blinking and alert circuit inside the bait holder. The length of wire to the surface would likely be a problem with this.
So I moved the circuit to the buoy and made the bait holder magnetic and put a reed switch inside the bait holder to trigger the blink circuit. This would probably work really well and be easy to waterproof.
I decided to do sketch an idea that came up when thinking about this and that was to add some auto thrusters so when the bait was disturbed a timer would start and then the pot would surface on its own.
I still love this idea and would at minimum love to put a camera in a crab pot, but I know others have done this already and I would say the video is totally worth the effort.