Description TF 115 was responsible for the harbor defense and surveillance units in the ports of Vung Tau, Cam Ranh Bay, Qui Nhon, Nha Trang, and Vung Ro, Inshore Undersea Warfare Groups (IUWG) 1, 2, 3, 4, and 5, operated a total of 16 large personnel landing craft, 25 Boston Whalers, and 8 picket boats in Operation Stable Door. The 45-foot picket boats, which began to reach Vietnam in June 1967, carried a crew of one officer and five men and two .50-caliber machine guns, twin-mounted. In each port the units constructed harbor entrance control posts and equipped them with radios and surface search radars.
