Abstract: The present invention relates to the use of water-based control fluid in subsea systems as barrier fluid for electric motors (2) coupled to subsea pumps (1). For that purpose, a hose (HFL) (12) is arranged between an umbilical termination unit (9) and the electric motor (2) of the submersible pump (1), by means of a connection plate (MQC) (7). This installation makes more rational use of the space on the floating production unit by reducing the number of devices required for the implementation thereof, and by facilitating logistics regarding these products and devices.