we actually troll open water i n early spring with mini beetle spin type baits.usually some shot a couple feet up the line till we determine the depth they are holding at.the bigger gills seem to school in open water over various depths.i think it is a follow the hatch thing.this lake i fish every spring has a lot of coves and arms that are deep.we run slow right down the middle and catch lots of em.crappies and white bass too