Abstract: A device for reducing underwater sound energy and propagation, whereby the device includes at least one bubble generation unit and an air conduit for supplying pressurized air to the bubble generation unit, whereby the bubble generation unit has a fluidic oscillator for generating one or more pulsating air flows from a constant air flow, and whereby preferably the fluidic oscillator has an adjustable oscillation frequency, and a method for using such a device for reducing underwater sound propagation, whereby the air conduit and the bubble generation unit are placed underwater, whereby pressurized air is supplied to the air conduit and whereby air bubbles are generated by the bubble generation unit.

Abstract: A belt for reducing the drag of a hull of a floating vessel, whereby the belt includes a belt body extending in a length direction (L), whereby the belt has, a sequence of bubble generators which are embedded in the belt body, whereby the belt has an air channel for supplying pressurized air to the bubble generators, whereby the air channel extends in the length direction (L), whereby the bubble generators are connected to the air channel, whereby the belt body is made of a flexible material. Also disclosed is a device having such a belt and a method of reducing the drag of a hull of a floating vessel using such a belt.