A real test of the capabilities of Weiss commenced on 2 October when she departed Subic Pay en route to Vung Tau, Republic of Vietnam for combat operations termed Bold Dragon VII and VIII. Her mission was to become an over the horizon support ship for SEAL operation in the IV Corps area of Vietnam. The operations tested the endurance of the ship and her crew, special light SEAL support craft (LSSC) boats were stowed in the ships Welin davits, 75 SEAL officers and enlisted personnel and numerous assorted types of support equipment were crowded aboard the ship. The combat operations were conducted along the coast of the Mekong Delta on the south China Sea and on Phu Quoc Island in the Gulf of Thailand. During the operations Weiss provided berthing, messing, communications support and naval gunfire support for the SEAL when they were in the field. Weiss fired her guns in anger for the first time since the Korean War on 6 and 7 November when she fired 347 rounds of 5"/38 and 1750 round of of 40mm into enemy held areas of Phu Quoc Island. Upon completion of the operations, Weiss sailed for and upkeep period at Subic Bay arriving 11 November.

At the conclusion of the short upkeep period, Weiss sailed from Subic Bay on 20 November for a well earned rest and relaxation period in Hong Kong, British Colony. During the import period in Hong Kong, personnel enjoyed the sights, night life, and shopping which the port has to offer. At the conclusion, the ship returned to Subic Bay, arriving on 28 November.

Weiss was underway for Vietnam operations on 3 December. After arriving in Vung Tau and a fast trip up and down the Long Sok River (Saigon River) to load SEALS and their equipment, operation Bold Dragon IX was commenced. Weiss's roll was the same as Bold Dragon VII and VIII, ie. serve as a floating over the horizon, support ship for SEAL operations in the Cau Mau peninsula of South Vietnam and on Phu Quoc Island. The operations commenced with little difficulty and continued into 1969.