A physical model investigation was performed to establish a stable breakwater design for use in the proposed construction of 58 offshore breakwaters at Erie, Pennsylvania. The study was conducted at a geometrically undistorted linear scale of 1:22, model to prototype. Monochromatic and irregular wave conditions were generated to simulate design wave conditions at still-water levels of +1.9 ft and +7.5 ft, low water datum. Incident and transmitted wave heights were measured throughout the investigation. Tests indicated that the armor design proposed by the sponsor was adequate. This design was characterized by an armor layer consisting of stones with weight range resulted in an unstable structure. A final breakwater design armored with 2.9- to 7.5-ton stone was also tested and found to be adequate. A presentation of wave transmission measurements is included.