On 17 February 1977, "Barb" stood out of San Diego on her way to the Far East. On the first leg of her voyage, she participated in the multinational exercise RIMPAC 77 and then made a two-day call at her former home port, Pearl Harbor, at the end of the month. She then embarked on the transit to Subic Bay, the duration of which was extended by exercises with TG 37.9 and TG 77.3. The submarine arrived in Subic Bay on 18 March but returned to sea almost immediately for the passage to Chinhae, Korea. Along the way, she took part in exercises with units of the Japan Maritime Self-Defense Force and with elements of the South Korean Navy. "Barb" visited Chinhae from 29 March to 1 April and then called at Hong Kong between 11 and 14 April. From Hong Kong, she set out for the Marianas, exercising with units of the Royal New Zealand Air Force and United States Navy patrol aircraft along the way. The submarine spent the period 20 April to 9 May in port at Guam, then put to sea for the first of two special operations that she conducted in May and June. "Barb" reentered Guam on 24 May, but returned to sea the following day to begin the second and longer of her two special operations. That employment lasted until the end of June at which time she put into Subic Bay for a week of liberty before heading back to the United States on 7 July.