Over the past 100 years major clearance of mangroves and dredging activities have taken place in Careel Bay, Crystal Bay Winji Jimi Bay, Winnererremy Bay and Mc Cars Creek. Current boating activities on Pittwater not only generate waves but also affect the wave angle and the form of breaking on the shore. Given the volume of vessel movements this can modify the sediment movement along the shoreline causing both erosion and accretion. Low-cost solutions for shoreline protection range from mangroves in the more sheltered regions to cobbles and beneficial re-arrangement of existing shoreline rocks in the more exposed areas.