Before revision:  The mobility index calculation used in this study, has a worldwide extent and is based on the computation of cumulative navigated miles (CNM ) of all ships reporting their position and navigational status via AIS . We compare 2020 mobility levels to those of previous years assuming that an unchanged growth rate would have been achieved, if not for COVID-19.
After revision:  The mobility index calculation used in this study, has a worldwide extent and is based on the computation of cumulative navigated miles (CNM ) of all ships reporting their position and navigational status via AIS , number of active and idle ships, and fleet average speed. To highlight significant changes in shipping routes and operational patterns, we also compute and compare global and local density maps. We compare 2020 mobility levels to those of previous years assuming that an unchanged growth rate would have been achieved, if not for COVID-19.