A marine loading arm comprising at least one fluid transfer line having a line end fixed to a base (21) and a moveable line end provided with a coupling (26) adapted for connection to a target duct (35), the coupling having at least three degrees of freedom (A, B, C) relative to the base and at least one member of the group coupling / target duct or a member immediately neighboring one at least of the members of the group coupling / target duct comprising at least one means (33, 34) for providing information on positioning of the coupling; and a control device (1) for the movement and positioning of the coupling (26), comprising at least three actuators (27, 28, 29) each for controlling the movement of the system in a degree of freedom, wherein each actuators consists of an electric motor and is provided at an articulation of the loading arm providing one of the degrees of freedom, the control device furthermore comprising calculating means (41) adapted to: calculate the relative positioning of the coupling directly relative to the target duct according to the information provided by the positioning information means of the coupling, calculate control instructions to give to each of the electric motors such that their combined movements result in a movement of the coupling aimed at bringing the coupling closer to the target duct, apply said control instructions to bring the coupling closer to the target duct, reiterate the three preceding steps until the coupling is presented in front of the target duct in a position for connection.