Purpose. The purpose of the study consists in obtaining modern accurate data on the bottom relief features and the granulometric composition of bottom sediments in Limenskaya Bay region of the Southern Coast of Crimea.

Methods and Results. The samples of the surface layer (0–5 cm) of bottom sediments were taken using the Peterson grab sampler in September 2022. The granulometric composition of bottom sediments was studied using the decantation and scattering method. The hydroacoustic research of the seabed was performed from the small vessels of Marine Hydrophysical Institute and the Black Sea Hydrophysical Subsatellite Polygon in 2022 and 2023. The Lowrance Elite FS7 instrument which includes a built-in single-beam echo sounder (200 kHz) for determining the sea depth, the side-scan sonar (455/800 kHz) and the global satellite navigation system receiver for defining the coordinates was applied. It is noted that at present, the sea bottom in the coastal part and in Limenskaya Bay sublittoral is covered with the unevenly distributed sedimentary material of heterogeneous composition. In the shallowest part (0–10 m), the boulder-pebble forms of sediments are widespread, their active movement is a result of storm impact and anthropogenic activity.

Conclusions. The predominance of gravel fraction in the western and eastern study areas results from the landslide-prone coastal morphology. In the deeper parts (10–15 m) of Limenskaya Bay, the bottom is covered mainly with the well-sorted sand sediments. At the depths exceeding 20 m, the proportion of silt fraction increases, which is consistent with the previously studied features of general dynamics of sediment fractions in this region. Having been deciphered, the results of bottom relief hydroacoustic scanning in the coastal zone made it possible to outline the boundaries of boulder-pebble area, as well as to estimate the predominant sizes at various parts of the bottom.