Ocean mass variations appear on many different temporal and spatial scales which exacerbate the measurement with just one instrument. To improve the understanding of ocean mass variations, data derived from four different measurement systems were combined in a joint inversion. The joint inversion of GRACE, GPS and modelled ocean bottom pressure (OBP) performed by Rietbroek et al. (2009) is extended in this study by including in‐situ OBP from the database of Macrander et al. (2010). The extension of the joint inversion leads to a local improvement of the correlation between in‐situ OBP data withheld from the inversion and the one obtained by the analysis. This improvement is seen for example in the tropical Atlantic where the correlation coefficient increases from about 0.4 to 0.6. The inversion is performed in spectral domain and major changes in the standard deviation of the spherical harmonic coefficients occur between degree 5 and 25. The global mean ocean mass variation (degree 0) is just slightly changed. The strongest changes in variance are seen in the Arctic Ocean and the North Atlantic. In conclusion, the addition of in‐situ OBP to the inversion of Rietbroek et al. (2009) changes the mass variation mostly locally with no major influence on the global mean mass variation.