A hydrographic survey ship is a vessel designed to conduct hydrographic research and survey. Nautical charts are produced from this information to ensure safe navigation by military and civilian shipping.

The Project 872 Finik Class hydrographic vessels has a length of 61,3 m, a width of 10,8 m and a draft of 3,2 m. The vessel has a standard displacement of 939 tonnes and full load displacement of 1190 tonnes. It has a maximum speed of 13,4 knots, range of 4356 nmi at 11,8 knots and an endurance of 15 days. The vessel is equipped with 2 Mius navigation radars, Rumb radio direction finder. The vessel is powered by two 960 hp Cegielski-Sulzer 6AL25/30 diesels rotating two controllable pitch propellers. It also has two 143 hp mSS5e electric motors, and three 192 kW diesel generators. The vessel has a crew of 27 and it can carry a research team of 9 persons.

Small hydrographic survey vesses of this project in two modifications served on all fleets of the USSR and later - the Russian Federation. In total, 23 vessels of this type were built for the Navy.

Hydrographic Survey Vessel GS-398 laid down at the Stocznia Polnocna Shipyard, Gdansk, Poland (yard No.872/13), launched 09 February 1980, commissioned 10 June 1980 and was assigned to the Black Sea Fleet.

In 1981, the vessel was upgraded to a trial ship and renamed to OS-265. It was part of the 184th marine research station, based on Balaclava, Crimea, was intended for transportation of fighting dolphins.

From 01 January 1996, the vessel was reclassified to military transport, and renamed to VTR-75.

In 2004-2005 Tuapse Shipyard upgraded the vessel according to Project 872E (Ecological Monitoring Vessel). The conversion project was developed at Vympel Design Bureau. On 24 April 2005, a acceptance certificate was signed with rename to Petr Gradov.

The ship regularly monitors water area around the fleet’s moorage sites, coastal assets, and military units of Southern Military District. In 2011, Petr Gradov has carried out over 20 control raids around BSF basing sites, including those near Caucasus Mountains. That made possible to conduct ecological monitoring of aquatic environment with mapping of pollution zones, provide ecological maintenance to the fleet’s combat training activities, and collect data for environmental audits according to Russia’s international commitments.

Now in service.