The Great Lakes Dredge & Dock (GLDD) rock installation vessel for the US offshore wind industry.


An SRIV designed to carry up to 20,000 metric tons of rock. Using an inclined fall pipe system to secure the precise subsea installation of rocks, this creates a scour protection for offshore wind turbine foundations. The vessel boasts an overall length of 140.5 metres (461 feet), a breadth of 34.1 metres (112 feet), and accommodation for 45.

Vessel Type
Owned By
Great Lakes Dredge & Dock Co. LLC (GLDD)
Built By
Partner yard

Primary Specifications

140.5 m
34.1 m
Draught (max)
7.0 m
Speed (max)
12 kn
Note: Specifications may have changed since the original completion date.

Ship history

The Acadia will be the only Jones Act-compliant rock placement vessel in the U.S. commercial fleet and is a critical vessel needed to develop U.S. offshore wind projects. The vessel enables specialised subsea operations, making it an essential tool for offshore wind projects. With its large and robust aft deck area, the Acadia is a highly flexible asset for GLDD.

Ulstein celebrates GLDD's SRIV ‘Acadia’ keel laying at Philly shipyard


2020, Dec: Basic design contract
2021, Apr: Integration engineering contract
2021, Nov: Shipyard selected
2023, Jul: Steel cut 
2024, Jun: Keel lay


Ulstein Design & Solutions B.V.