Floating Breakwater Modeling and Design for Oyster Point Marina

Abstract

Oyster Point Marina in San Francisco Bay, California has recently been modified to allow ferry service within the marina basin. The modifications included reconfiguring the entrance channel which resulted in increased wave activity within the marina basin and subsequent damage to vessels and docks. A numerical model study of wave penetration into the marina basin and potential mitigating measures was conducted and concluded that floating breakwaters within the marina basin could be used effectively to reduce the wave energy to acceptable levels. One unique aspect of the floating breakwaters within the basin is that the wave reflection had to be minimized in order to maintain acceptable wave heights in the main marina fairway. Most applications of floating breakwaters to protect small craft harbors are not concerned with the reflected wave energy as it would normally propagate into open water and not typically interfere with navigation. A large scale physical model study was undertaken to evaluate various floating breakwaters. The model study included monitoring the reflected wave conditions as well as the transmitted waves. Modifications to standard floating breakwaters were tested to evaluate the energy dissipation which would result in reduced wave reflection and the transmitted waves. The results of the physical model study were used in a Boussinesq model of wave penetration into the marina basin simulating the measured wave transmission and reflection as porous boundaries at the multiple floating breakwater locations.