For more than a year the Gibraltar force under Admiral Niblack performed service which reflected high credit upon that commander, his officers, and his men. During this period of time it escorted, in co-operation with the British forces, 562 convoys, comprising a total of 10,478 ships. Besides protecting commerce, chasing submarines, and keeping them under the surface, many of the vessels making up this squadron had engagements with submarines that were classified as "successful." On May 15, 1918, the _Wheeling_, a gunboat, and the _Surveyor_ and _Venetia_, yachts, while escorting a Mediterranean convoy, depth-charged a submarine which had just torpedoed one of the convoyed vessels; we credited these little ships with sinking their enemy. The _Venetia_, under the command of Commander L. B. Porterfield, U.S.N., had an experience not unlike that of the _Christabel_, already described. On this occasion she was part of the escort of a Gibraltar-Bizerta convoy. A British member of this convoy, the _Surveyor_, was torpedoed at six in the evening; at that time the submarine gave no further evidence of its existence. The _Venetia_, however, was detailed to remain in the neighbourhood, attempt to locate the mysterious vessel, and at least to keep it under the water. The _Venetia_ soon found the wake of the submerged enemy and dropped the usual depth charges. Three days afterward a badly injured U-boat put in at Cartagena, Spain, and was interned for the rest of the war. Thus another submarine was as good as sunk. The _Lydonia_, a yacht of 500 tons, in conjunction with the British ship _Basilisk_, sank another U-boat in the western Mediterranean. This experience illustrates the doubt that enshrouded all such operations, for it was not until three months after the _Lydonia_ engagement took place that the Admiralty discovered that the submarine had been destroyed and recommended Commander Richard P. McCullough, U.S.N., for a decoration.