method and water submerged device for generating a force under water . the device includes a low pressure recipient configured to contain a volume of a first fluid at a low pressure volume , an inlet connected to the low pressure recipient and configured to exchange a second fluid with an external enclosure , and a valve connected to the external enclosure and the inlet and configured to separate a pressure source in the external enclosure from the low pressure recipient . when the valve is open , such that there is a flow communication between the external enclosure and the low pressure recipient , a pressure imbalance occurs in the external enclosure which generates the force and the second fluid from the external enclosure enters the low pressure recipient and compresses the first fluid .