NOVELTY - The device comprises an electronic circuit (52) and a battery (53) provided for powering the circuit. The circuit and the battery are included in a block of hydrophobic material. The device further comprises an actuator included in the block of hydrophobic material, a control panel, a unit for communication between the electronic circuit and the control panel, and a pressure sensor and/or a temperature sensor (55). The actuator is controlled by the electronic circuit and powered by battery. The block of material includes a block of resin (51).    USE - The device is useful in a buoyancy compensator and in a closed-circuit rebreather (all claimed), and in a marine environment.    ADVANTAGE - The device comprising the battery avoids contact of metal parts with water.    DETAILED DESCRIPTION - The device comprises an electronic circuit (52) and a battery (53) provided for powering the circuit. The circuit and the battery are included in a block of hydrophobic material. The device further comprises an actuator included in the block of hydrophobic material, a control panel, a unit for communication between the electronic circuit and the control panel, and a pressure sensor and/or a temperature sensor (55). The actuator is controlled by the electronic circuit and powered by battery. The block of material includes a block of resin (51). The battery is a type of charging electrical contact battery or induction charging battery. The communication unit comprises a unit for transmitting/receiving optical signals or radio and/or acoustic signals connected to a fiber optic cable. The actuator is a motor driving a compressor. The compressor comprises a pipeline within the block of material. The rotor of the motor is housed within a pipeline and embedded in the block of material. The actuator comprises a valve or a plug adapted to be remotely controlled. An INDEPENDENT CLAIM is included for a buoyancy compensator.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of an electronic device.    Block of resin (51)    Electronic circuit (52)    Battery (53)    Temperature sensor (55)    Optical sockets. (56a)