According to Sean Hoernke, FLW tournament pro and FIELD & STREAM Total Outdoorsman Challenge competitor and host, if you can skip a rock, you can execute the slingshot cast.
"As more lakes get developed, boat docks become a more important spot to fish," says Hoernke. "But most guys are just working the edge. Slingshotting lets you penetrate the cover."
 Squat or kneel so you're close to the waterline, and point your rod at the target, keeping it parallel to the surface.
 Open the bail and let out half a rod length's worth of line. Hold the line against the rod with the index finger of your rod hand or pinch it between your thumb and index finger. Grab the lure with your other hand and pull it back, loading the rod, until the bait is about even with your side. "You really want to load the rod with a big parabolic bend," says Hoernke. A 6½-footer with a medium-light action works best. "Grab the lure behind the hook," adds Hoernke. "Otherwise you're asking to get stuck."
 Let go of the lure, timing the release of the line with your other hand as you would on a normal cast. "Aim so the lure hits the water right before the dock," says Hoernke. "The lure should skip across the surface like a stone."