2 pound ice fishing line for a tippet material or 7X or lighter. Take an ice fishing jig and tip it with a wax worm. No agressive casting or you will loose the waxie. If the thoughts of live bait and the waxie don't do it for you, try some scent on the fly. Good luck. Finding the active feeders is the key. You very well might have spooked them. Try not to run the motor right up on top of them. Electric trolling motor to within casting distance, but not right on top of them. Good luck.

Rick