Matinicus Harbor in Matinicus Isle Plantation is located on the eastern side of Matinicus Island, approximately 15 miles south of Vinalhaven Island and 23 miles southeast of Rockland Harbor. Matinicus Island is the largest of a group of islands off the mouth of Penobscot Bay. The harbor is used by local fishermen and mail and freight boats from Rockland Harbor.
The project consists of a 450 foot long breakwater extending southeasterly from Youngs Point to Indian Ledge. The breakwater was completed in 1911 and underwent major rehabilitation in 1962.