The left side of the 18th hole at Quail Hollow, site of this week's PGA tournament, features a narrow creek running up most of the length of the hole. Late in the 3rd round, I saw two players, Justin Rose and Martin Flores (who was tied for the lead at the time) hook their tee shots left of the hazard, only to see the ball bounce off the bank and into the creek.
Both players took a drop that not too many amateurs know about: Under 26-1c, the player may determine the point where the ball last crossed the margin of the hazard, and drop at "a point on the opposite margin of the water hazard equidistant from the the hole." This was the best choice for Rose and Flores, since it gave them a much flatter and cleaner lie than dropping on the side where the ball crossed into the hazard.
This picture shows the severe bank the players would have had to play off of had they dropped on the left side. Two club lengths from the right margin of the hazard gave them clean, level lies, and I think might have even gotten them into the fairway.
I tried explaining this option to a player in a tournament I worked last season, to be met with a very confused stare.