11.  Soon echoes of human voices can be detected bouncing off the placid waters.

12.  The placid waters are popular for water skiing and sightseeing excursions.

13.  Underneath the placid waters running through his veins bubbles a passion for the game.

14.  Whatever the outcome of the debate, she said, she is delighted that her letter has roiled the placid waters of Phi Beta Kappa.

15.  Skate had a good look at the cause of potential disease, the hundreds of bloated bodies still drifting in the placid waters, simmering in the tropical heat.

16.  So while their boats bobbed around in the placid waters, crew members relaxed.

17.  The arrival of personal watercraft has roiled the placid waters of the surfing community.

18.  While their boats bobbed around in the placid waters, crew members relaxed.