Great Lakes Dredge & Dock Corporation (Great Lakes) is a provider of dredging services in the United States. Great Lakes provides dredging services in the East, West, and Gulf Coasts of the United States and worldwide. The Company also owns NASDI, LLC (NASDI), a demolition services provider located in the Boston, Massachusetts area. The Company has a 50% interest in Amboy Aggregates (Amboy), a sand dredging operation in New Jersey and a 50% interest in TerraSea Environmental Solutions, (TerraSea) an environmental remediation services business. The Company operates in two segments: dredging and demolition. During the year ended December 31, 2011, the Dredging Operations segment generated approximately 83% of total revenues and the Demolition Operations segment generated approximately 17% of total revenues. During 2011, the Company sold the dredges Northerly Island and Victoria Island along with a parcel of land in Channelview, TX.