The bill to fix the USS Miami Submarine has jumped to 450 million dollars.
The sub was heavily damaged by an arsonist in May while dry docked at the Portsmouth Naval Shipyard in New Hampshire.
The figure is 50 million more than the first estimate and the Navy says it could go up another 45 million.
Casey Fury - a civilian worker at the shipyard - is accused of setting the fire.
According to NCIS investigators, Fury started the fire to get out of work.
He's currently awaiting trial where he could face life in prison.