A floating lowering and lifting device (1) includes a floating structure (2) and a lifting unit (3) lowerable from the floating structure (2) towards the sea bed, the lifting unit (3) having a chamber (5) with at least one gas-inlet opening (9) in its wall (27) and an equalization opening (23, 25) in its wall (27), a gas supply (13) being connected to the gas inlet opening (9) The device includes a control element (15) connected to the gas supply (13) for controlling a gas supply rate to the chamber (5), wherein the chamber (5) includes a releasable coupling member (7) for releasably attaching to a load (8).