Abstract: The invention relates to a simplified single mooring device for mooring and loading-unloading tanker vessels, comprising a submarine conduit for the supply or the discharge of a fluid, to which is connected at least one flexible pipe through a conduit end module, comprising a device for mooring the vessel and designed with a sufficient mass to withstand the pull from the vessel, and the flexible pipe being connected at least temporarily to conduits provided on the vessel through a hose end module including at least one rotary joint. The device allows the use of a buoy and of a submarine rotary joint to be avoided, while at the same time being of very simple design.