The invention relates to a floating lowering and lifting device having a floating structure and a lifting unit lowerable from the floating structure towards the sea bed, the lifting unit having a chamber with at least one gas-inlet opening in its wall and an equalization opening in its wall, a gas supply mechanism being connected to the gas inlet opening, the device having a controller connected to the gas supply mechanism for controlling a gas supply rate to the chamber. The chamber has a releasable coupling member for releasably attaching to a load and is connected via a lifting cable to a take up device on the floating structure for lengthening and shortening the lifting cable.