Bobby and Sally are on the high seas. Each in their own respective boats. Sally has a range finder and is able to determine that Bobby’s boat is 12 meters away. She also notes that any time Bobby’s boat is on a crest, hers is in a trough. And when hers in on a crest, hers is in a trough. She also notes that whenever she is in a crest or trough, there is always a crest among her boat and Bobby’s. If each boat repeats it’s up and down motion 8 times, every six seconds. What is the wave’s velocity?