Hanwha Philly Shipyard has handed over Acadia, the first U.S.-flagged, Jones Act-compliant subsea rock installation vessel, to Great Lakes Dredge & Dock, according to Hanwha Philly Shipyard.
Built in Philadelphia, the vessel gives Great Lakes a purpose-built asset for subsea rock placement at a time when U.S. offshore energy projects require domestically qualified marine capacity.
Acadia is designed to carry and place rock on the seabed to protect offshore wind turbine foundations, power cables, telecommunications cables and pipelines. Great Lakes will first deploy Acadia on Equinor’s Empire Wind 1 project off New York, before moving the vessel directly to Ørsted’s Sunrise Wind project, also off New York. It is then expected to move to Europe for rock installation work for a major offshore wind developer, with employment covering most of 2027.
The vessel is 140.5 metres long, or 461 feet, with a moulded beam of 34.1 metres, or 112 feet. It has a rock hold capacity of 20,000 tonnes, DP 2 positioning, ABS class and accommodation for 45 people.
Great Lakes Dredge & Dock is a U.S. dredging contractor and offshore energy infrastructure company. It became a wholly owned subsidiary of Saltchuk Resources on 1 April 2026 in a transaction valued at about $1.5bn.
Hanwha Philly Shipyard is a U.S. shipbuilder based at the Philadelphia Navy Yard. Founded in 1997, it is part of South Korea’s Hanwha Group and builds commercial and government vessels for the U.S. maritime market.
