The first time I used a light in the water at night was interesting. We anchored just before dark, dropped the light about 10' deep and waited. It was overcast and cool enough that the sketters didn't eat too much. Around 2300 the minnows started showing up and within 10-15 min there were thousands of them under the boat. About 2400 the dark shapes of bigger fish began to show deep. About that time, the big full moon popped out from behind the mountian and trees. When that moonlight hit the water, everything vanished and did not come back. So that tells me to fish the dark of the moon or at least to fish only quarter moon so there isn't so much light on the water. Also, Joe is right about white lite in the boat. Keep above surface light to a minimum and if possible keep it in the boat, not over the boat. Good luck and tight lines.