She returned to the Philippines from the second Vietnam tour of the year on 1 February, and embarked American UDT men and a Philippine underwater operations unit to participate in bilateral reconnaissance exercises near Legaspi, Luzon, between 3 and 9 February. A visit to Hong Kong, availability at Subic Bay, and another survey tour off Vietnam followed in late February and early March. Her last combat operation of the deployment began on 20 March when she came under the operational control of the amphibious ready group for Operation Jackstay, a combined surface and helicopter-borne amphibious assault on Viet Cong guerrillas in the Rung Sat Special Zone. The operation began on 26 March and continued through 6 April, at which time "Weiss" headed back to Subic Bay for upkeep. Later that month, she departed the Philippines and headed home. She made a stop at Pearl Harbor along the way and arrived in San Diego on 14 May. The ship remained in port for the next five weeks engaged in the usual post-deployment leave and upkeep. On 28 June, she stood out of San Diego and shaped a course for San Francisco, where she began regular overhaul at the Bethlehem Steel shipyard. She remained there until 9 November when labor problems in the civilian yard forced her to shift to the San Francisco Bay Naval Shipyard to ensure timely completion of the overhaul. Repairs completed, the warship exited the yard on 9 December, and headed back to San Diego, whence she operated until late February 1967. On 24 February, she departed San Diego for the western Pacific. After stops at Pearl Harbor and at Guam, the ship entered Subic Bay on 20 March. "Weiss" operated in the Philippines for almost two months conducting surveys and reconnaissance training. In mid-May, she made a liberty call at Hong Kong and then returned to Subic Bay late in the month. On the 28th, she departed the Philippines with a detachment of UDT-11 embarked, and set a course for South Vietnam, arriving at Vũng Tàu on 31 May. Following briefings there and at An Thoi, "Weiss" began a series of coastal surveys to determine suitable landing beaches and canal entrances for amphibious operations. That duty lasted until 10 June, at which time she headed back to Subic Bay. She remained in the Philippines from 10 to 21 June, and then once more got underway for Vietnam. She conducted another series of coastal surveys until 3 July, and returned to Subic Bay for a week's rest and relaxation. The ship arrived back in Vũng Tàu on 15 July and began her final series of surveys, completing them on the 31st.