Two boats are anchored in the harbor, separated by a horizontal distance of 20 m. The boats bob up and down as the waves enter the harbor. When the first boat is at its highest point, the second is also at its highest point and there is one wave crest between them. Each boat makes exactly 5 complete up-and-down cycles every 30 s. The vertical distance between a boat's highest and lowest point is 2.2 m.