J506 is a Type 925 submarine support ship later renamed/renumbered to 863 Yongxing Dao (might have gotten another new name/number recently) and was part of the recovery fleet in the South Pacific in 1980, back when the PRC and the West had much friendier relations because of the Soviet threat. She was brand new at that time, now is one of the oldest active vessels in PLAN. HMAS Jervis Bay was a converted ferry that was returned to civilian service in 1994.