A system and a method for transferring cryogenic fluids; e.g. transferring liquefied natural gas (LNG) between an offshore receiving/loading station (13) and an onshore facility (11). The flowline system which can be submerged in water is comprised of a main transfer conduit (15) which is positioned within an outer jacket and a return conduit which is positioned within the main transfer conduit. The annulus between the jacket and the main conduit is insulated. Both the main conduit and the return conduit include means which allow the respective conduits to expand/contract with temperature changes.