Golf Whistle

This is the undo button for a shot that got away. Call the ball back and it reappears where you played it from, and your card takes an extra stroke for the trouble.

Since the penalty costs the same as a normal swing, it only wins when the ball has landed somewhere that would cost you several strokes to escape: down a chasm, sitting in water, or buried in a cave under the fairway. The bigger reason to carry one is the ball you simply cannot get to anymore. Without the whistle that hole is over. Buy it before your first ambitious course, not after you have already lost a Golf Ball to lava.