INS Sagardhwani (A 74) is a marine acoustic research ship (MARS) owned by the Naval Physical and Oceanographic Laboratory (NPOL), maintained and operated by the Indian Navy, and based at Southern Naval Command, Kochi. The ship was built by Garden Reach Shipbuilders & Engineers, Kolkata, launched in May 1991, and commissioned in 1994. It is similar in design to the Sandhayak-class survey ships, but with the superstructure positioned amidships and a helipad forward.