Indonesia has many small islands to manage for sustainable development goals. The urgency of this research lies in seafloor classification technology using acoustic technology. Seafloor classification plays a crucial role in mapping and monitoring marine ecosystems, marine resource management, research, military operation, and engineering activities. We used multibeam echosounder (MBES) for seafloor quantification and characterization in Pari Island waters, North Jakarta, Indonesia. MBES instrument provided bathymetry information and backscatter data. The bathymetry data provide seafloor depth while the backscatter data are used to classify seafloor sediment. The sediment grab sampling were taken to validate the seafloor acoustic backscatter. We found in this study area, the measured acoustic backscatter strength of MBES is a function of the signal frequency, incident angle, and sediment type.