DonJonShipbuilding will construct the 185,000 barrel barge and BAE Systems will build the tug.
Delivery of the coastal chemical & petroleum unit is expectedin the first half of 2016, New York-listed Seacor said in a statement.
Daniel Thorogood, president and COO of Seabulk Tankers,said: "This ATB order brings additional capabilities to Seabulk's growingfleet and positions us to service existing and developing customer requirementswith modern, efficient equipment."
Seabulk