Abstract: A mounting assembly is for installing a thruster on a variety of marine vessels having a liner and a hull separated from the liner by a gap. A through-bore in which the thruster is to be installed axially extends through the liner, the gap, and the hull, and because of differences in manufacturing and/or materials at least one dimensional variance exists in at least one of the liner, the gap, and the hull amongst the variety of marine vessels. The mounting assembly has a base member configured to be installed on the liner over the through-bore and an adjustment member that is adjustable and fixable in place relative to the base member to accommodate installation of the thruster at different axial positions in the through-bore so as to accommodate said at least one dimensional variance.