I have kept a green underwater light on at my slip at night for years. It's good for crappie and white bass. You can see the white bass swimming in the light. The crappie stays in the shadows of the light. They may be in the deeper water under the light circle or along the edges of the light circles.
I only turned it off was when I slept in my houseboat. I would turn it off then at midnight due to all the boats that would fish the green light at night while I was trying to sleep. I don't mind people in boats fishing my green light if they are quiet and didn't wake up those sleep in their houseboats. Unfortunately too many show no respect for those who provide the green lights when they fished the green lights late at night.
We are all born ignorant but one must work really hard to remain stupid. -Ben Franklin
PROUD MEMBER OF TEAM GEEZER
Any day I'm fishing is a good day, regardless of what I catch.