Abstract: The device, which can be used on merchant vessels having only a course reference, comprises on a base (18) a mounting having bearing orientation means and supporting a gyroscopic assembly with two degrees of freedom, whose outer cardan transmission (28) has an axis of rotation (axis X) perpendicular to the bearing axis, its inner cardan transmission (36) having an axis of rotation (axis Y) at right angles to the axis X and being connected to the antenna during aiming. The gyroscopic assembly comprises a single flywheel (41) of considerable kinetic force in relation to the inertia of the antenna (10). Each cardan transmission has a torque motor (30,38) controlled by a loop whose feedback signal is delivered by an orientational pickup (40, 32) of the other cardan transmission. The means (24, 42, 46, 20) for orientation around the bearing axis are adapted to ensure substantially the aiming of the antenna in bearing, and therefore to retain the gyroscopic assembly close to the canonical position.