This dataset contains hydroacoustic measurements collected by the Simrad EK60/EK80 echosounder of RV Polarstern during its drift across the Central Arctic Ocean during the MOSAiC expedition (PS122) from October 2019 to October 2020. We provide data for the frequencies 38, 70, 120 and 200 kHz (synchronized), and 18 kHz. The data are uncalibrated raw measurements of acoustic backscatter in the Simrad raw format. The data should only be used after careful consideration of the disclaimer on appropriate scientific use of the data provided with this dataset.