Raceland-based Adriatic Marine LLC has signed a deal with C&E Boat Rental LLC to acquire three offshore supply boats, one 220-feet long and two 170-footers, and will take delivery in September of another 220-foot vessel being built for C&E.

Terms of the deal were not disclosed.

The additions will boost Adriatic’s fleet to 21 offshore supply boats with an average age of four years. In July, Adriatic expects the delivery of 12 supply boats: seven 220-footers; two 260-footers; and three 200-foot boats capable of burning methanol.

The vessels are only part of Adriatic Marine’s expansion plans. The company has ordered four 260-foot-long ocean-going deck barges, which are expected to be delivered in October. The company has been providing offshore supply services in the Gulf of Mexico since 2007.