assault across Roanoke Sound, and three others occupied an earthwork near the geometric center of the island. Wise made one other contribution to the defense. He found some pile drivers, and was able to impede the sound between Forts Huger and Forrest by a double row of piles, augmented by sunken hulks. The barrier was still being worked on when the attack came. The Confederate Navy also made a contribution to the defense. Seven gunboats, mounting a total of only eight guns, formed the Mosquito Fleet, commanded by Flag Officer William F. Lynch. Wise, for one, believed that their net contribution was negative. Not only were their guns taken from the forts on the island, but so were their crews. He gave vent to his feelings after the battle: Captain Lynch was energetic, zealous, and active, but he gave too much consequence entirely to his fleet of gunboats, which hindered transportation of piles, lumber, forage, supplies of all kinds, and of troops, by taking away the steam-tugs and converting them into perfectly imbecile gunboats. Despite Wise's disapproval, the Mosquito Fleet was part of the defense, and the Union forces would have to deal with it. Union offense A short time after Hatteras Island was captured for the Union, Burnside began to promote the idea of a Coast Division, to be composed of fishermen, dockworkers, and other watermen from the northeastern states, and used to attack coastal areas. He reasoned that such men were already familiar with ships, and therefore would be easy to train for amphibious operations. Burnside was a close friend of General-in-Chief George B. McClellan, so he got a respectful hearing. Although Burnside had initially intended to operate in Chesapeake Bay, in the hands of McClellan and the War Department his ideas were soon transformed into a planned assault on the North Carolina interior coast, beginning with Roanoke Island. An unspoken reason for the change of target was the mistaken belief that pro-Union sentiment was being suppressed in North Carolina, and an invasion would allow them to express their true loyalties. When it was fleshed out, the invasion of North Carolina came to be known as the Burnside Expedition. As recruiting progressed, Burnside organized the Coast Division into three brigades, led by three friends from his Military Academy days. Brig. Gen. John G. Foster led the First Brigade, Brig. Gen. Jesse L. Reno the Second, and Brig. Gen.