4. Waves approach a breakwater as shown in Figure 2. Compute the maximum free surface elevation at each of the three locations a, b and c if the incident waves have offshore height 0.8 m and period 9 seconds. You may assume the breakwater is perfectly reflective and the depth is constant at 7 m for all locations North of the breakwater. [10 marks] depth= 7m + 200m 100m 100m Breakwater 100m 60 200m 1: 15 slope in direction Incident waves normal to breakwater crest lines Figure 2: Waves approaching a breakwater as described in question 4. Top view (North upwards). The seabed slopes at 1:15 towards the South (i.e. in a direction normal to the breakwater)