U.S.-Flagged Subsea Rock Installation Vessel Acadia Floats Out at Hanwha Philly Shipyard
The first U.S.-flagged, Jones Act-compliant, subsea rock installation vessel designed to support the offshore energy sector marked a milestone as the vessel was floated out at the Hanwha Philly Shipyard. The vessel, named Acadia, has faced delays in its construction and challenges as the U.S. offshore wind market largely collapsed, but owners Great Lakes Dredge & Dock Corporation continue to express confidence as they expand their strategy for the vessel.
The Acadia is engineered to transport and install up to 20,000 metric tons of rock on the seabed. This is a vital part of offshore energy projects, providing scour protection for subsea infrastructure, including cables. Great Lakes initially ordered the vessel at a cost of $197 million in November 2021, focusing on the offshore wind energy sector to protect offshore wind turbine foundations and cables.
“The company proactively expanded its strategic target markets for the Acadia to include oil and gas pipeline and power and telecommunications cable protection, as well as international offshore wind,” Great Lakes wrote in a recent stock exchange filing.
Projects and Future Engagements
Great Lakes has contracts to support Equinor’s Empire Wind I and Ørsted’s Sunrise Wind, both fully permitted projects and under construction. Work began on Sunrise Wind in 2024 and Empire Wind I in 2025. Additionally, the company has a reservation for the vessel from a third, unnamed offshore wind project in the United States.
However, a contract to support Empire Wind II was canceled by Equinor. Great Lakes expects the current projects to keep the vessel engaged through 2026 and is in discussions with clients for new offshore energy projects domestically and internationally for operations in 2027 and beyond.
Construction and Dispute Resolution
Work on the Acadia began in the summer of 2023 with a ceremonial first steel cut attended by President Joe Biden. Assembly began on May 2, 2024, and the vessel is expected to be delivered early next year, marking the completion of Great Lakes Dredge & Dock Corp’s major new build program.
The owner and Philly Shipyard were in dispute over construction delays, but after the sale of the yard to Hanwha Ocean was completed in December 2024, Great Lakes withdrew their complaint and pursued private dispute resolution, possibly through arbitration as outlined in the construction agreement.
Impact on Offshore Wind Industry
The Acadia is one of several large vessels ordered in the U.S. to support the offshore wind energy sector. The offshore wind industry has spurred the construction of various vessels, including turbine installation vessels, offshore support vessels, and crew transfer vessels.
With the Acadia set to play a crucial role in protecting subsea infrastructure for offshore energy projects, Great Lakes Dredge & Dock Corporation remains optimistic about the vessel’s future prospects in the evolving offshore energy market.