I've fished for (and caught many) gar with a snare rig. Its basically a 40lb mono snare loop with a minnow hanging from a small hook and leader in the center of the snare. The rig is suspended below a bobber. When the gar takes the small minnow the noose closes and they're caught.
Schools of gar just below the surface are a common sight in very warm weather.
Fun to catch, these prehistoric looking fish.
RG