A converted offshore support vessel (OSV) has been delivered as the newest freight and passenger ferry in the Woods Hole, Martha’s Vineyard, and Nantucket Steamship Authority fleet and will be commissioned on May 16.
The Aquinnah is one of three sister ships purchased by the Steamship Authority in 2022 from Hornbeck Offshore Services, Covington, La., to replace an aging trio of open-deck freight vessels.
The OSVs — formerly known as HOS Lode Star, HOS Shooting Star, and HOS North Star — were built by Atlantic Marine, Inc., Jacksonville, Fla., and previously served the oil and gas industry off the Gulf Coast.
The Aquinnah, along with the Barnstable and Monomoy, was converted at Alabama Shipyard, Mobile, Ala. The Barnstable was commissioned in December 2024, and the Monomoy is currently being converted and is scheduled to be commissioned later this year.
The Steamship Authority has experience with the OSV conversion model, having taken this path with the Gay Head, Katama, and Sankaty in the late 1980s and early 1990s. Those three vessels, like the new ships that will replace them, were originally built to serve the offshore oil and gas industry in the Gulf of Mexico before being repurposed for ferry service in the U.S. Northeast.
“The purchase and conversion of available OSVs is the most efficient, rapid, and cost-effective path to upgrade our fleet and best serve the vehicle and freight transport needs of island residents and visitors,” Steamship Authority general manager Robert B. Davis said in a statement in 2022. “The similar design of the vessels also promotes economies of scale through interchangability of vessels for service needs, inventory of spare parts and crew training.”
The purchase and conversion costs for Barnstable, Aquinnah, and Monomoy were made possible, in part, via an agreement with the Cape Cod Regional Transit Authority that yielded $28.1 million in federal funding.
As part of the conversions, several significant modifications were made to the vessels, including altering the vessel length from 240' to 245' and modifying the stern area to align with the transfer bridges. New structural subdivision bulkheads and tonnage bulkheads were added to bring the vessels under 1,600 grt. The width of the vessels was increased by adding sponsons, and new fuel tanks were installed. Additionally, the main deck area was reconfigured to accommodate passenger seating and restrooms, and new HVAC equipment was installed. Overhauls of the bow and stern thrusters were carried out, and the ship hulls and superstructures were blasted and painted.
“The end result is the same across all three ships,” a spokesperson for the Steamship Authority told WorkBoat.
The Aquinnah is outfitted with two Caterpillar engines, each rated at 2,000 hp; two controllable pitch propellers; and three 950-hp thrusters.
The vessel also boasts state-of-the-art radar, communications, and navigation systems, two marine evacuation systems and a rescue boat, and an interior passenger area with seating for approximately 80 passengers, the Steamship Authority said. The vessel can carry the equivalent of approximately 50 automobiles per trip.
