Correct Answer : INS Sandhayak
INS Sandhayak, the Indian Navy’s oldest Hydrographic Survey Vessel, was decommissioned from the Navy at Visakhapatnam on July 4, 2021.
The vessel is 40 years old and has conducted more than 200 major hydrographic surveys. It has also been a part of important operations like ‘Operation Pawan’ in Sri Lanka (1987), Operation ‘Rainbow for Humanitarian Assistance’ (2004) etc.