A breathing device for divers that includes a breathing tube exhibiting an end having an inclined opening, an obturator that is mobile between an open position and a closed position of the opening of the end, a float that activates the obturator, a first articulator that communicates the obturator to the tube, a second articulator that communicates the float to the tube. The first and the second articulators can each exhibit a respective hinge axis to the tube. The hinge axis to the tube of the second articulator can be more greatly distanced from the end of the tube relative to the hinge axis to the tube of the first articulator.