At a special meeting Thursday morning, the Steamship Authority board of governors is expected to vote on a shipyard contract to convert two of the boat line’s three recently-purchased service vessels into SSA freight boats.

While the dollar amount of the contract is still under negotiation, it’s likely to be sharply higher than the $8 million to $9 million per vessel Steamship Authority management had estimated when buying the boats last year.

The lowest bidder for the job, Alabama Shipyard in Mobile, Ala., last month pegged the conversion cost at more than $20 million apiece, an estimate the SSA has been working to reduce by extending the timeline for delivery.

Steamship general manager Robert Davis and director of marine operations Mark Amundsen have traveled to Mobile for in-person talks at the shipyard this week, authority treasurer Mark Rozum told the port council Tuesday morning.

A virtual meeting has been scheduled for Thursday at 9:30 a.m. to potentially award the shipyard contracts.

The Steamship Authority bought the first two of three identical offshore service vessels last year from Hornbeck Offshore Services in Louisiana, where they had been in storage after seeing a few years of duty in the Gulf of Mexico oil industry.

The SSA later exercised an option to buy a third vessel. The boats, which have been renamed M/V Aquinnah, M/V Barnstable and M/V Monomoy, remain in Southern waters.