By the morning of December 30, Sherman had concluded that resuming the attacks at the same location would be fruitless and he and Porter planned a joint army-navy attack on Drumgould's Bluff to the northeast, hoping that the steep bluffs would provide cover for his men as they advanced. It was imperative that such a movement be started in secrecy so that the Confederates would not shift their defensive forces. The movement commenced on December 31, but was called off in heavy fog on January 1, 1863.