A wave of H o= 3.0 m and T = 7 s is propagating toward the shore where the bottom contours are all straight and parallel to the coastline.

A wave of Ho = 3.0 m and T = 7 s is propagating toward the shore where the bottom contours are all straight and parallel to the coastline. If a water velocity is umax = 20 cm/s is required to initiate sediment motion, what is the greatest depth in which sediment motion can occur?