If you're boat is equipped with modern electronics, immediately waypoint the spot as soon as a rod goes down. Depending on where your GPS puck is mounted, this might not give you an exact mark, but it’s worth doing anyway. The more critical action is to cast—or have your fishing partner cast—a heavy lure right on the spot where the rod went down, making sure to keep the bail open or clutch in free spool so the lure stays put, acting as a reference point if the boat moves. With the spot marked, I quickly tie on a snagging rig (a weighted treble) and cast a little past the spot where the rod went over. Then I start making slow drags back to the boat. Over the years I've learned that the faster you act, the better the odds of getting the rod back.