I'm not a night time crappie catcher b/c of blood sucking and biting bugs and think the underwater light would draw in less blood suckers.

I think making a underwater light would be fairly simple.
A glass tube/plastic,cork or rubber stopper,LED light and wire.
Drill a hole in one of the corks or rubber stoppers for the wire going to the LED and seal all points.
Why would this not work?

I even thought once about putting a light in a gallon glass jar until my pea brain said want be enough room for a light b/c of all the rocks it would take to sink it lol.