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. Hydrographic survey vessels also conduct surveys of the seabed and the underlying geology.

The Project 862 Yug-class hydrographic vessels has a length of 82,5 m, a width of 13,5 m and a draft of 4 m. The vessel has a standard displacement of 1842 tonnes and full load displacement of 2435 tonnes. It has a maximum speed of 15,9 knots, range of 8650 nmi at 13 knots and an endurance of 40 days. The vessel is equipped with two Don navigation radars, Khrom-K IFF, Rumb radio direction finder, MG-13 underwater communication station and MG-26 Khosta underwater communication station. The vessel is furnished with advanced sonars, meteorological and chemical-hydrographical equipment and two hydrographic survey boats. The vessel is powered by two 2200 hp Cegielski-Sulzer 12AB25/30 diesel rotating two controllable pitch propellers. It also has two 143 hp mSS5e electric motors, four 480 kW diesel-generators and one 220 kW diesel generators. The vessel has a crew of 58 and it can carry a research team of 12 persons.

Hydrographic survey vesses of this project served on all fleets of the USSR and later - the Russian Federation. In total, 18 vessels of this type were built for the Navy.

Hydrographic Survey Vessel Gidrolog laid down at the Stocznia Polnocna Shipyard, Gdansk, Poland (yard No.862/9), commissioned in 1979 and was assigned to the Black Sea Fleet.

In 1997 the ship was transferred to the Baltic Fleet. Decommissioned in 2015.