The BalMarGrav project, co-financed under the Interreg Baltic Sea Region 2021-2027 Programme, aims to improve southern. This task is very important due to the decision of the Baltic Sea Hydrographic Commission (BSHC) to implement a common height reference system called Baltic Sea Chart Datum 2000 (BSCD2000), which will be based on a geoid model determined by measurement soft the Earth’sgravity. The BalMarGrav project involves organisations from 8 countries of the Baltic Sea region (11 partner institutions) to jointly ly rework gravimetric measurements made in the 1960s–1980s in the southern and eastern parts of the Baltic Sea. These campaigns were mainly carried out with the support of the Soviet Union. During the period of independence from the Soviet Union and the political transition, much of this data was forgotten or underutilised. During the BalMarGrav project, over twelve historical marine gravimetric sources were identified for further re-processing and homogenization of the data with nowadays surveys of the gravity field in the Baltic Sea region. Guidelines and methods are developed tore- calculate the historical gravimetric data to modern geodetic and gravimetric reference systems.