The naval vessels, on the 24th of January, lay off the mouth of the Yazoo, and from there to the neck of land opposite Vicksburg, where the army under Grant's orders was disembarking. A few days before Porter had been obliged to withdraw the gunboats, because the coal supply of the fleet was exhausted. During their absence eleven Confederate transports that had been employed on the river between Vicksburg and Port Hudson went up the Yazoo for supplies, and were there caught by the unexpected return of the squadron, a serious embarrassment to the enemy. At this time the vessels of the squadron near Vicksburg, or within easy reach, were: The Benton, Cincinnati, De Kalb, Louisville, Mound City, Pittsburg, and Chillicothe, ironclads; Rattler, Glide, Linden, Signal, Romeo, Juliet, Forest Rose, Marmora, light-draughts; the Tyler and Black Hawk, wooden armed steamers; Queen of the West, Monarch, Switzerland, Lioness, rams. During the following month the Carondelet and Indianola, ironclads, joined the fleet. The heavy vessels remained near the army and the principal scene of operations, but some of these lighter vessels and rams, with others farther up, were scattered at intervals along the river from Island No. 10 downward, cruising up and down, keeping off guerillas, preventing contraband traffic, and convoying transports and supply boats; in a word, keeping open the communications of the army. A small squadron of five light-draughts performed the same service constantly in the Tennessee and Cumberland Rivers. General Grant arrived on the 30th of January. The army were busy digging on the canal across the neck, which had been begun the previous summer, and the various plans as yet discussed had mainly reference to turning the right flank of the Confederates. Meantime there was no hindrance to the complete control of the river between Vicksburg and Port Hudson by the enemy, who continued their traffic across it and by the Red River unmolested.