Built in 1988, the vessel has a displacement of 6,600 tons, and a length of 364 ft (111 m).

Both ships feature a vertical shaft about two meters in diameter, which opens from the main deck into a special room, from which an acoustic receiver or a transmitter can be lowered to below the waterline by means of a winch.

The vessels were used for experiments on the long-range propagation of sound in the ocean.

[4] The vessel ran aground west of the Astronomical Society Islands in the Gulf of Boothia,[5] Nunavut, Canada in August 2018.

[9] — описание 29-го рейса судна со слов д-ра А. Переса (Бразилия)