The Sandhayak-class survey ships are a series of eight vessels built by Garden Reach Shipbuilders and Engineers (GRSE), Kolkata and Goa Shipyard, Ltd., Vasco for the Indian Navy.

[2][3] The vessels equipped with four survey motorboats, two small boats and are powered by two diesel engines with a top speed of 16 knots (30 km/h; 18 mph).

The ships are designed to undertake shallow coastal and deep oceanic hydrographic survey and collect oceanographic and geophysical data required for the production of digital navigational charts and publications.

Besides carrying out their primary role of hydrographic survey, they can also assist in times of war and natural calamities as troop transports and casualty holding ships.

[8] The third ship in the class Nirupak was decommissioned after 38 years of service on 29 January 2024 in Visakhapatnam.