There is disclosed a floating system positioned in a body of water having a water bottom, the system comprising a host member floating on a surface of the water; a flotation module floating under the surface of the water; a flexible hose connecting the host member to the flotation module; and an elongated underwater line structure, comprising a top portion connected to the flotation module; a bottom portion extending to the water bottom and adapted to connect to a flowline lying on the water bottom; and at least one of the top portion and the bottom portion comprising a catenary configuration.